This has been a few months ago now but one night my bf and I relaxing on the couch at my place watching a movie. Around midnight, my roommate came home along with two friends of hers, a guy and girl I'd never met before. We said hi and she introduced them, then said the three of them were going out to the back porch to hang out.
A little later our movie ended, and my bf and I just sat on the couch for a while talking and he gave me a foot rub, when all of a sudden we heard what sounded like a moan. We were confused, because it sounded like it was in the apartment, but thought my roommate and her friends were out back. We shrugged it off and figured it was some them laughing out back or something, but then a few seconds later we heard another moan, and it sure sounded like it was in the apartment.