She stands there sweating and dripping her juices and slightly screaming. Her legs get tired and she can't stand anymore but has no choice. She stands there until Robert comes back. He is finally back at 11.00pm but it looked like days for Silvia. "Tired?" he asks he walks in. "Hmm" she makes the sound behind the towel. He turns on the lights and studies her body carefully. "You are so helpless" he remarks and removes the chain from the hook and her neck. She collapses to the ground kneeling on the floor. He removes the towel from her mouth and asks her whether she enjoyed it. With less energy to talk, she answers "Not really" softly. "Not really, what?" he screams. "Not really Master. Sorry" she replies immediately with some sudden fright. "You still haven't learned respect and there is a long way to go" he says and slowly removes the clamps from the breasts and lifts her up and then removes the clamps in her pussy. She sighs in relief. Suddenly he puts the clamps in her pussy again and she screams in pain and shock. "What? Relief? Haha" he says. "You shouldn't do all that, understand young lady?" :"Yes Master, Okay Master" she says in pain. He removes the clamps from he pussy again. He touches her breasts and caresses them. Then reaches the pussy and slightly touches it. He suddenly slaps it hard and she screams in pain and surprise. "That hurts huh?" he asks laughing. He takes off the blindfold and she looks at him for a second and then put her head down in embarrassment. He bends down and removes the straps from the ankle but leaves the ones in her wrists still on which holds her hands behind her. He drags her by the arm and leads her to the bathroom. Knowing that she is still wet and dripping and waiting to cum so badly, he asks her "Do you want to cum?" "Yes Master, please. I really can't bear this anymore" she says. He then asks her to stay there and went away. She stayed there for about 15 minutes wondering what he was doing and going to do to her next. She wanting to cum so much, she waited without patience. He came back with a bottle of Vaseline. He strapped the ankles again and removed her straps in the wrist. He asked her to lift the arms high up behind crossing each other below her head. She did so and he strapped her back. He applied the Vaseline to his fingers and then took some more and put it in her pussy. He slowly inserted his finger into her pussy opened her clitoris and the inner layer. She was squirming and wiggling her hips. She was moaning as well. He slowly penetrated in and out slowly and she was now moving so much. When her moans got so loud, he stopped. "Can't you just let me cum?" she shouted. He stared at her right in the eyes. "I'm sorry...ah Master, I just really want to cum, please don't do this to me anymore. I just can't resist any longer" she cried with tears dropping from her eyes. "No respect for me means no mercy for you" he said and washed his hands removing the Vaseline. "Please, I'm really sorry Master" she cried again. "Beg me until I think you deserve it" he said into her ears. "She was already dripping so badly and sweating by the humiliation. She pleaded again and again but to no avail. After almost 20 minutes of pleading, he said "Okay, but not the easy way anymore" he said and walked away. He came back in 10 minutes with a leather strap, the nipple clamps and a dildo. "I will spank you to cum, is that okay? That's your only way to cum now. I'll also put the clamps on your nipples and insert this dildo into your ass. What do you think?" he asked smiling at her. "A small question made things so worse for me" she thought and said "Okay Master" she said with tears weeping from her face. He applied the nipple clamps again and twisted it. She screamed in pain as the nipples were already so sore. He turned her around and applied the Vaseline to her ass and slowly penetrated his finger in and out for a while. She started moaning again. He took the dildo and put some Vaseline in it as well and inserted it in one push until it was in as deep as it could get. "How do you feel now, Silvia?" he asked smilingly. "Well let's start the spanking" he said. All the spankings she ever received before was in her buttocks but this is the first time she is spanking in her pussy. She screamed like hell when the first one landed. He liked to look at her reaction when he spanked her before but he couldn't as she faces front when he spanked her at the back. Today, he saw a much better reaction when she was facing him. He kept the strap in rhythm and he made it harder each time and she couldn't stop screaming and moaning at the same time. After 10 strokes, she hasn't cum yet. She was in pain more than pleasure. He paused for a moment letting her catch her breath. He started again and SMACK "Ouch" SMACK "Ouch" laid another ten more. She still didn't cum and was crying profusely now and moaning lounder and louder. He paused again and let her relax a bit so he can spank her more before she cums. With some mercy for her, he turned the vibrator in the dildo on and she couldn't stand and wiggled her hips and the whole body was moving. He started spanking again and she was moaning louder again and trembled. When he hit the 29th stroke, she exploded her orgasm right to the bathroom floor. He spanked her another five more times and she collapsed to the floor on to her own orgasm. He turned the dildo off and slowly removed it. His cock was erect and wanted to fuck her but since she was his sister, didn't want to cum into her. He went to the other bathroom and masterbated. He exploded his load and he then cleaned himself and came back to see her. She was still on the floor but now facing up. He held her by the arm and lifted her up as she was tied and couldn't help herself. He then removed the ankle and wrist straps and asked her to clean the mess on the floor and then take a shower. She washed the floor clean and then took a shower thinking about what had happened today and just couldn't believe it. She soaped herself and relaxed for almost 1 hour in the tub. She massaged her sore pussy and nipples. She dried herself and came out. Still naked, went to her room and looked for her clothes. Robert came behind and said "You are not going to wear anything and going to sleep naked. Since you didn't ask my permission to wear clothes, I assume you disobeyed me again. For that, you will have these dildo's in your pussy and asshole until morning" he said looking at her in the eyes. He then put Vaseline in the dildos and inserted into her pussy first then the second one into her asshole. She was aroused all over again and started squirming as he inserted them in to her. He then strapped her ankles and wrists again in case she wanted to go out or remove the dildos. "Have a good sleep and I'll see you tomorrow with more surprises" he said as he turned on the two dildos. It started vibrating but he put it in low so that she can still manage to sleep. He turned off the lights and air-conditioners as she was moving in the bed with two dildos vibrating in her. He left their room to sleep in his parents' Master Bedroom. After sometime, she was so tired but she came once before she slept.