I will start with mine which I remember fondly from time to time. Years ago when I was much younger and with W-1 i was at a party and everyone was having sex with each other. I had just had sex with this woman and we had moved from the bed to a chair and she was sitting on my lap. The room was quite dark but you could see enough to see other people. We had moved to a chair to free up the bed for others. We were just sitting there cuddling in warm afterglow of post coital cuddling. I was holding her and rubbing her tits somewhat and a few other rubs. I could not touch her clit as it was still too sensitive from the love making just completed. Her husband came into the room and walked around. He stopped by the bed and watched briefly and then approached us. He was naked and had a huge erection. We were all naked. He walked over and his waif asked him "honey have you had any?" He said no he had not and she said here let me help you out. While sitting on my lap she started sucking his dick. I got into the action by kissing her shoulder and the back of her neck, nibbling on her ear and kissing her cheek. All the while holding her tightly. I would whisper into her ear and encourage her. Near the end I told her not to let a single drop get away. I continued to play with her titis and by now could finger her pussy. He started moaning and let go a huge cum in her mouth and sure enough she did not lose a drop. He thanked both of us and pointed out to her that It looked like I was ready again. I was hard as a rock. We made our way back to the bed and I was back in her pussy in no time. Oh, those were the days.

I must add that this is the mental image I conjure up most frequently when I wake up middle night and want. Stimulates me good. This one and the time a buddy of mine and i fucked a girl I was going with at the time. Fucked and sucked both of us.