When I was in college (i'm now 24) I had a single dorm room connected by a bathroom to another single dorm room (essentialy a two bedroom suite wihtout a common room). I had a great room mate and we were best friends instantly. My girlfriend and I hung out with my roommate and his girlfriend all the time.
One night I was going down on my girlfriend and my roommate boldly barged in after getting out of the shower with just a towel wrapped around him. My girlfriend screamed in protest and scrambled to cover herself with a sheet. He was smiling like a cat that just ate a canary and I was laughing my ass off.
He started to leave my room and my girlfriend yelled "No fair" in protest, and then told him that he had to take of his towel. Without hesitation he did. He then protested that she was now covered and he wasn't so she pulled of the sheet covering her. He got an erection in a blink and boldly went over and tweaked one of her nipples so she squeezed his balls with authority. She let go as he dropped to his knees in pain.
Well it rapidly escalated from there. She made some comment about not being nice to her nipple and he said something like let me make it up to you, a leaned forward and started to suck on her nipple. I'm sitting there still laughing but kind of bewildered about the scene before me.
At this point my girlfriend stopped protesting and was clearly enjoying the situation. I really didn't know what to do but for whatever reason decided to resume licking her pussy. Well, she really got into it and within two minutes had a powerful and loud orgasm.
My roomate turned to me with an I can't believe it grin, said something about being nice to her nipple, stood up and stuck his hard cock towards her face. She reached for his balls and started stroking them gently and asked him if that felt better. He told her not really so she started stroking him slowly with her hand.
At this point I was about to cum just from watching this whole scene so I knelt between her legs and started fucking her. She instantly started thrusting her hips up and down to meet my thrusts. I came in less than a minute because I was so turned on.
There was an awkard minute after I came where my girlfriend was still stroking his cock and looking at me kind of sheepishly. It was clear she wanted to fuck my roomate, I was definately getting into the whole scene, and I knew my roomate would fuck her in an instant if he had the chance. So I asked my roommate if he wanted a turn.
He damn near pushed me out of the way and started nailing her. He was pounging her hard and she was clearly loving it. She grabbed my cock and pulled me towards her mouth and then started sucking it. I was hard and horny again in a flash.
When my roommate came we rolled her over so I could fuck her doggie style while she sucked his cock. He played with her tits and rubbed her clit. We kept altenating each time we came and chain fucked her like that for at least an hour. She came as many times as we did.
As far as sloppy seconds go... I have to say I loved it. Her pussy was so wet, slippery, silky smooth, hot and making the most erotic squishy noises... oh yeah... I loved it (and so did she). I don't know why, but we never repeated that night.
Even though we talked about chain fucking his girlfriend it never happened. She was just too reserved to even approach her and we both knew it. But, once when he was away on an internship she stopped by because she was lonely but that is another story! The picture is of me and her while roommate took the pic.