I've spanked four people in my life. 3 girlfriends and 1 friend.
The first woman, with her I was very young and tentative, a missed opportunity really. Looking back, she really wanted me to spank her bare bottom, and I just didn't get it. I spanked her very mildly one time, despite the fact that she rolled over for me and bared her bottom. I mean, looking back, she really was asking for it. But I was just young and dumb. Regret!
The second woman was very up front about her wish to be spanked and for me to make it hurt. I used my bare hand and later used a wooden dowel, about 1/4 inch thick, which usually left raised welts on her cheeks. Sometimes, in between strokes, I would spread her cheeks a little with one hand and press the tip of the dowel against her anus, poking inside just a bit. She loved that. She always wanted me to then fuck her in the ass afterwards, which I was more than happy to do. She loved playing doctor too. She was the most "bottom focused" girlfriend I ever had. She never spanked me but she did fuck me with a strap on a few times.
The third one, she never asked to be spanked, but it happened because I ordered her to go into the bedroom and lie on her belly and wait for me. This girlfriend liked when I paid attention to her ass but was very passive, never said "no" to anything, but never ever initiated anything herself. So I went into the bedroom with a long wooden ruler, I think like 18 inches. I laid it on the bed next to her so she would see it. She saw it but didn't say anything. I told her I had to pull her pants down to give her a spanking. She quietly said "ok". I pulled her jeans and panties down to her knees, exposing her lovely round white bottom. I gave her 10 across those soft cheeks, leaving nice pink marks. She didn't cry out, but she was breathing very heavily by the end. I felt between her legs and she was completely wet, so I told her she was a "good girl", took her pants all the way off, then kissed and licked her V until she came.
The fourth woman was not my girlfriend. It was an odd situation, one I never would have dared to try when I was younger like in my 20s. This incident happened when I was in my 30s. She was a good friend back in high school. We lost touch a bit over the years but she got back in touch when she was applying for a job in Seattle, near to where I lived then. She asked if she could stay at my place for the days she was in town for interviews and of course I said yes. Though I liked her and trusted her, the one thing about this woman which was always very annoying was how she'd monopolize a conversation. So when we went to dinner the last night, I invited another couple along, friends of mine, and this woman basically spend the whole evening telling us about her past jobs, current job interviews, her plans for the future, etc. She didn't ask my friends anything about themselves or listen to them. It was a bit embarrassing and I was kind of mad on the drive home. And I remember thinking "I really should say something to her" because I was mad and had nothing to lose, we'd become quite comfortable with each other again over those few days, I didn't care if she got upset because actually it was something I'd wanted to tell her since high school. Then I got another thought. Though I'd never dated her, and didn't we were compatible romantically, she was very pretty and had a lovely body (pale skin, long auburn hair, athletic), and my nasty male brain thought "in a perfect world, this woman should be spanked for her behavior." Honestly, for those last 10 minutes of the drive, even with her talking about whatever to me, I just tried to think if I had the balls to make it happen.
Once home, I told her flat out that I thought she was rude during dinner, talking only about herself. She immediately became upset, not at me but at herself. She admitted something I thought she'd always been ignorant of, that she could be completely self-centered in social situations. She kept apologizing to the point that I thought she was going to cry, because obviously she really was very aware of her problem. I told her that I thought she needed to do something that would help her not to act like that anymore, because both personally and professionally it was a liability. She agreed and said "like what do you mean?" I took a deep breath and said it, "Something that you won't forget." Pause. "I think you need a spanking." Longer pause. "I think you should let me spank your bottom." Wow, she just stood there actually not saying anything for once, looking down at the ground. I didn't know what to say or do so I just kept my mouth shut. After what seemed like 10 seconds she said, "OK." Couldn't believe it! OMFG.
Honestly, although she was Catholic, I have no idea if corporal punishment was part of her upbringing or what, but she was OK with this idea I guess. Anyway, I told her to lie on the couch and to pull her jeans down. Her panties were definitely not thongs, they covered her whole ass, and she lay there with her jeans around her ankles and her head resting on her hands looking straight ahead, not at me. I had a lot more confidence now and kneeled next to her, put my fingers inside her panties and said "these need to come down too". I thought she would resist or say "no!!" but she didn't say anything. So I pulled those down to her ankles too, leaving that lovely white and barely freckled bottom exposed to my eyes. Gorgeous sight it was, something I'd never dreamed I'd see. I heard her take a few deep breaths and drop her head, face into her hands. I quickly began spanking her, an openhanded swat on each cheek. Which make her yell a bit. Then I started in on a much harder spanking, enough to make my hand hurt. Enough to turn her pale ass quite pink pretty quick. The only other thing I said was, something like, "I hope this is something you will think about in the future." Something generic like that, but anyway, she nodded her head and said "Yes. Yes." Then because I couldn't resist I gave her a couple more, loud and hard, and then quickly pulled up her panties. Then I went and took a shower, mainly because I didn't know what else to do at that point. I was insanely excited and turned on by what had just happened, but also very anxious and unsure of what to do next. She didn't give off any vibe that she wanted this to become a sexual encounter. I masturbated in the shower because I was rock hard and also I didn't want her to notice my erection later. After I'd gotten out of the shower, I gave her a towel so she could shower too.
We didn't talk the rest of the night. Went to bed, in separate rooms, never saying any more about what happened. In the morning, I saw her off. She gave me a hug and said "thank you so much for everything." I wished her good luck and she took off. She never ended up moving to the Pacific NW, and I ended up moving out of the area eventually later on. We still email occasionally, but we've never seen each other since. Amazing as that evening was, part of me wishes it had gone further, but another part of me thinks that that's as far as she wanted it to go. Needless to say the picture of her bare bottom is forever in my mind and I'd be lying if I said I've never jacked off to that night's memory.