Me and my current girlfriend had been together for 3 months. Her name is Rebecca - but I like to call her Rebs. We met a year prior through some common friends and exchanged contacts back then. I liked here and felt drawn towards here from the very beginning, but at that time I felt a friend of hers was hitting on me and I didn't want to cause and friction between them so I backed down.

Some time later she happened to like several stories of mine on social media and I messaged here to see what she was doing. We end up talking for several days with no pause and soon after we started dating and ending up together. Life was great with her. We had common hobbies, shared the same love for life and adventure and we liked to spice things up (although it did took some time to open up about some of our fetishes). I felt that I could always talk, open up and be myself - without fear of judgment. Also I felt she gave me new perspectives and helped me know myself better.

Rebs was wild in the bedroom. I usually tended to be the dominant one - and I was displaying this with her as well. But with this girl it was always a constant struggle for power - and I loved it so much. She would let me pound her like hell while spanking her ass and scream my name like the world is about to end and this would be our last love making session only for her to get back up with a devilish smile, start to ride me while holding my neck tight. She wouldn't let me take charge - it was her time to rule. Sometimes when I would be fucking her missionary style she would bite my lip hard and start to spank my ass from the behind, leaving it red before we climaxed. I usually ending up giving her a dedicated spanking session after as an added bonus. It was perfect and it gave me the best orgasms of my life - with her sex was like a never ending party as we always seemed to have enough for another round.

Rebs was a nurse working at a local hospital. I was working from home - it was initially a little bit challenging to manage our relationships due to her shifts, but as we grow closer it was no longer a problem. One kink of mine that has stayed with me from my teenage years after having to do some treatment for an infection was a fetish for injections. And with Rebs having this switch side where she liked both being dominated and dominating and also being a registered nurse it seemed like I had hit a jackpot. However, I must confess I was still afraid to talk about this with here. She was great, I loved here, the sex was also great but other than some bondage, spanking and me playing a little with her ass we didn't really explore that territory further. The other thing I wanted to try with her - anal sex. I did played several times with up to three fingers in her ass and she seemed to love it. However, when I rubbed my dick near her back entrance she pointed it towards her sweet pussy so I dropped the idea. Still, I was curious to find out if she wanted to try it - her ass was beautiful and every time I gave her a massage I felt a huge urge to fuck her there.

One day after one of our usual sex session we were hugging and I finally found the courage to open up to her:

'Baby, there are some things I wanted to talk with you about' I said. 'Nothing to worry, some stuff I was thinking about trying in the bedroom - if you'd be willing to of course'

I heard her sweet voice:

'Baby, you know you can tell me everything and I won't judge. Tell me what you would like to try and we will see if we can work things about'

With some growing confidence, I replied:

'First one, do you think about trying some anal?'

She giggled.

'Yeah, I thought you will ask about that' She seemed relaxed, no concern. 'To be honest I did try anal before and I used to love it so muuch. However, before I met you I used to have this boyfriend and he was pretty rough in bed. I enjoyed sex with him, but it wasn't the same connection I feel with you. Not even close. He did fuck me pretty rough and my ass hurt for some weeks when sitting before it faded. So I was kind of afraid yo try after that. But, with you, all the ass play was great - and not only that, as I am sure you know - and it did not once hurt at all. So yeah, I think I am willing to try again, it just takes some time to gather back my courage'. She blushed.

I looked at her.

'You know I would never do something to hurt you. It would brake my heart.'

'I know baby' and she came close to me and kissed me.

I felt so close to her and so mesmerized that I almost forgot about the other thing I wanted to ask. She didn't. She never forgets.

'What was number two on the list?'

I panicked for a second. But I couldn't back down now. We had a policy of always being honest with each other and now that I mentioned it I knew she wouldn't drop it.

'Well, there was this fetish I had since my teenage years. It my sound pretty weird, but I had some infection and needed to receive an antibiotic treatment for several weeks. The nurse that came to my house to give me the treatment was pretty hot and every time she would give me the shot in my ass I would end up with huge erection. I liked the soft dominance vibe she would give me - she would make sure I received my treatment and she knew it would hurt but she would always make sure I was ok after. It kind of reminds me of you'.

She froze on my chest, not moving a muscle. I started to panic further. Fuck, why did I say that??!! What will she think of me now? Did I ruin everything?!

'Stay right here' she said.

She got up and moved to a different room. I didn't know what to do. Should I go after her? Should I wait? I was thinking how could I be so stupid to ruin the best relationship of my life.

She finally returned with a bag and put it on a night desk near the bed.

'Baby, I...'

'Wait!! I don't won't you to worry baby!' she replied. 'Sorry for my sudden reaction, I realize how it might have looked. Truth be told, I do a lot of shots - sometimes to hot guys with hot asses such as yours' She winked. I started to relax. 'I never saw it as something erotic. However, when you described how it made you feel I thought it was hot as hell. It kind of turned me on'

She grabbed a syringe, needle and a vial from her bag.

'And I want to do it to you. Now!'

I started to panic again. I knew I wanted to try it with her, but not that soon. To be honest, I was afraid of it - but I guess this was part of the pleasure. But I hoped I would have some time to prepare for the event at least.

'I don't know baby, not this soon. I mean, to be honest, I am little bit afraid. I thought you will give me some time, talk about it, plan it, maybe prepare for it mentally before'.

She smiled. 'Baby, it's ok to be afraid. I was always afraid before anal, but still loved it regardless. Trust me, I will take good care of you - but know this, I will make it hurt a little - maybe not as much as your antibiotic shots but I do have a special technique that I will use on you' The devil grin on her face returned 'But I do this because I know there can be a fine line between fear and pleasure. And your fear can sometimes heighten that pleasure. And trust me, I am a pro. You are safe with me taking care of your ass. So you have to choose mister - either now or who knows when I'll be in the mood fo this kinky play again...'

And again that smile. That devilish smile. I could never say no to it. And I knew she was right. I was both afraid and horny as hell. The perfect mix. And I trusted her. I loved this girl.

I moved the blankets off and lied flat on my tummy in the bed. I was only in my underwear.

'Ok, I am ready baby'

She started to giggle.

'Yees' she seemed to be more excited than me. She started preparing the injection.

'Ok baby, this is a B12 shot. It shouldn't sting that much - although my special technique might add a little extra for you' She winked.

I saw the red liquid that was about to penetrate my butt being ready for its job. Then, she replaced the initial needle with another one. Here my heart started to race again. This one was way larger.

'I figured out my big boy could take something bigger' I heard her saying.

She came near me and I heard the alcohol bottle opening. I could feel the familiar smell in the air. I knew it was happening know. She grabbed my underwear and pulled it down to my knees. My ass was now fully exposed. Then I felt the cold alcohol swipe on my left cheek. Then my right cheek.

'I want to keep you guessing, baby'. The devil inside her was taking charge again.

And I stood there it silence for several seconds, but it felt like minutes. Not knowing which cheek would take the big boy in. I was again feeling afraid as fuck - but horny as well. And I was enjoying every second of it.

Then, I felt the needle pressing. Left cheek it is. However, instead of a jab, the needle was slowly pressing on my skin, trying to get in. Suddenly, it popped, and I felt a sharp jolt of pain. And pleasure, like some sort of release. I was starting to leak precum.

Rebs started to push it slowly in. I was moaning, both of pain and pleasure.

'How is it?' she asked

'It hurts, but keep going'

After a few seconds I hear

'Ok, all in. Now be a brave boy.'

She started to inject the medicine quickly. My ass started to hurt like hell and my eyes became wet. For a moment, I didn't know how much it was left and was not sure if I can take it anymore. Then I felt the needle going out and she started to massage the spot. My left cheek took it like a champ.

She was smiling. 'Damn babyy, that was so hot. I haven't felt this rush in a while' she kept massaging the spot for a little bit and then she gave me a kiss on my damaged cheek.

I was standing there for a while and then I saw her going for her bag. She grabbed another set of vial, needle, syringe. I worried it might be a little bit too much for me for our first play round.

'Look baby, I don't know if my ass can take another one right now'

She smirked.

'Oh silly, I am sure you can take more than that. But don't worry, it is not for you. It's for me'

My excitement started to grow. I knew how she also loved to be dominated and based on what I experienced the previous few moments I knew she would love it. And it felt so hot to be able to return the favor.

'I figured out you shouldn't have all the fun. Come, I'll prepare this one and show you how to do it'.

I a few minutes, the roles were reversed. She was standing there with the beautiful ass exposed. To play fair, her injection would also be a B12 with the same monster needle.

'To be honest baby, know I am a little bit afraid as well' said she blushing in her sweet voice.

'It's ok baby girl. Someone once told me the fear amplifies the pleasure' I winced.

This time, there was no surprise, as she wanted to make sure I inject here right. She has already prepared it before hand and checked for bubbles while instructing me about the procedure. She told me how I should inject her and was watching over. I told her I will also use her special technique. She expected nothing less.

'Ok baby, are you ready'

I saw her smiling and heard a slight hesitant 'hmmm, yes'

I started whipping her right cheek and was ready to give her treatment.

'Be a brave girl now'

I started pushing. The needle popped through her skin and she left a soft moan. I started to push it further on slowly. She closed her eyes and the moaning continued, enjoying every second of it. I saw her left hand reaching bellow, starting to stroke her pussy. She was clearly loving this. The needle was all in.

I wanted to give her a break, so I started injecting her slowly. She kept moaning, her head rolling in the blanket. I love to see that desire in her burning so high in her. After half was already done, I decided the break was enough, so I started to inject the rest faster.

'Ohh, fuck' she said while biting the blanket'

I stopped for a second

'Too much?'

'Noo' she replied. 'Keep going'

And do I did. I finished the injection, removed the needle, and started to massage the spot.

Then, with my other hand, I started to massage her clit as well. After a few seconds, she started shaking and all her body collapsed. This was wild. I saw her climaxing before in ways that resembled a sex goddess, but nothing as intense as what I was seeing then. It felt like it took all her energy.

I capped the needle and then went back to her.

'How was it, my brave baby girl? Liked my technique?'

'10 out of 10. My ass cheek is sore as fuck but that was one of the greatest orgasms ever. Fuck baby, that was great! I love you!'

'I love you too!'

We started kissing. Then, she felt like it was her duty to return the favor, since I didn't finish yet. She grabbed the lube bottle. I was thinking she wanted to give my dick a smoother message. And so she did, at the begging.

I was enjoying her taking care of my dick, and I was laying with my eyes closed, moaning deeply and enjoying every second of it. Then I heard her.

'Hey baby, you know how we share every experience? There is something I want to try with you. I was afraid to mention it at first but I think you will really enjoy it and maybe we can give it a try now...'

I had no doubt I loved this girl and trusted her. And I was already in heavens. I did not hesitate one bit

'Baby, I trust you. If you want to try something, go for it!'

'Okk' I heard her giggling

I then heard the lube bottle opening. Then, I felt her fingers reaching down on my ass entrance. I was a little worried at first - never thought about trying ass play before. Then, I thought for a second: I trust this girl, we already did some wild things that day and to be honest in the past I did play with her ass and we did not reciprocate that experience yet. So I relaxed, and let her do her magic. If it hurts, I'll let her know.

She starting circling a little bit around my ass. Then, I felt one finger trying to make the push. I tried to relax and even started to push towards it, thinking it will help her. It soon popped in. It hurt a little, but not what I initially expected.

'Took it like a champ' she laughed

She continued to suck my dick while pushing the finger further. It did hurt a little, but I was really enjoying it. Then, I think it hit my prostate, as it starting to feel soo good. To my surprise she retracted her finger, only for then to return in double.

Rebs was now slowing fucking my ass with her fingers while blowjobing me. I couldn't last any longer.

'I'm cuminggg'

She started to pick up the pace while I exploded in what was the wildest orgasm ever. She continued even when I was finished and I felt something I've never felt before. A second orgasm. I didn't really believe this was possible for me

Rebs was smiling with loads of cum hanging from her mouth. She came next to me and gave me a sweet kiss, making sure she shares my body liquids with me in the process.

'I told you we share everything, right?

I didn't mind, I fucking loved this girl. We ended up sleeping in each others arms.

The next morning, when I woke up Rebs was already ready, preparing some pancakes for breakfast. After we ate, she told me about this idea she had this morning.

'Remember baby how at the begging of our relationship we used to play strip poker and the one who lost and was totally naked had to do some favor for the other?'

I smiled

'How can I forget that?'

The devilish smile appeared again.

'Here's what I was thinking. Same play, different ending. The loser this time must do a challenge, taking up the sub role, the winner gives the punishment' She started to slowly dance towards me

'And I was thinking we should incorporate some of our new found kinks: I have some more intense shots that we could give each other and I know we both love spanking. Also, I looked up some toys that I think we can incorporate in our play'

She handled me the tabled. The basked was already full: cuffs, a paddle, some butt plugs, candles, a vibrating dildo with some beads like structures on it ... and a strap on.

'I know how much you want to fuck this' and she lifted her t-shirt and parted her cheeks to show me her beautiful pink backdoor. 'And you might get to fuck it. But I also want to fuck yours now and if I win... I will'

She put her face near mine and watched me intensely in the eyes. No devilish smile, this time she was asking seriously

'Are you sure you are ready for this, mister?'

She already knew my answer.

'Count me in' I said and kissed her.