My girlfriend invited me to visit her family for New Years Eve. As my much as I do like my girlfriend, there is absolutely no denying that her sister is WAAAYY hotter.
She is about 170 lb, but spread out over a 6 foot frame, so no excess weight. She goes to the gym often, is really into fitness, so she is actually a sexy kind of muscular. In previous visits I have had a very 'hard' time not gawking if she came back from a run, her small but shapely breasts nipping out of her sports bra, her abs christened with sweat, and her tight ass flexing underneath her yoga pants. She has that slightly wavy (not too curly, not too straight) shoulder length hair that hits the sweet spot for me as well.
Anyways, you get the idea....hot as fuck chick....makes feel like I got the short end of the stick sometimes. She has this long distance boyfriend over in the Netherlands that she Skypes pretty often. Of course, since we live in separate cities, there aren't many opportunities to record. In fact, I wasn't even thinking about it or planning on it over the holiday....but DAMN I wish I would have been more prepared.
After a nice New Year's dinner, their mom invited us all to spend the night. Each sister got lodged upstairs in their childhood bedrooms, while I was set up with a couch in the downstairs living room. It all started when their cat accidentally woke me up early in the morning around 4-5am. I just got up to pop my back and use the bathroom when I heard the unexpected sound....
"ohhhh shit..." it came floating the down the stairwell with that tense and airy sound that accompanies someone under heavy pleasure

I could hear my heart pounding in my ears from the excitement. I worked on myself some, but couldn't fully enjoy it, because I was too nervous about getting so worked up I might tip somebody off. If only I could have had a recorder to capture the moment and play it back for my enjoyment later.
I could hear him saying some things through the computer, but I couldn't quite make it out. My mind's eye kept imagining her body tensing in sync with her sighs. I didn't hear a vibrator, so she must have been working on herself manually. She was probably at it for awhile before I woke up, because her unintentionally loud, but quickly stifled orgasm reverberated throughout the hall shortly after this whole thing started.
From there I heard some giggling, and crawled back to my couch to sleep. I of course haven't said anything to my girlfriend or the sister about what happened. But I really need to find an excuse to attend a family gathering soon. And I hope to be better prepared next time...