So by the time this happened, me and my girlfriend were together for about a year and her best friend was also one of my best friends. We’ll call my girlfriend Catherine and our mutual best friend Lauren. Me and Catherine both were best friends with Lauren for about a year and I always thought Lauren was extremely hot. Sweet, short, Asian girl with nice big tits but the thing was she had a super good moral compass so I knew nothing would ever happen. She wouldn’t cheat ever in a million years or home wreck and most girls say that and don’t mean it but she was the one girl I could see actually meaning it. Hell, she wouldn’t even cheat on a school test. However, after her boyfriend and her broke up she kind of changed. I only noticed her cheating on tests consistently but I still never thought she’d do anything to jeopardize anybody’s relationships.. especially not mine and my girlfriends. But this is where it gets juicy. Maybe a week into our summer after graduating, my girlfriend thought it’d be fun if we invite her over and we all hang out so I said sure. I invited both of them over and it was normal at first. We just talked for a bit and then we started talking about getting Lauren a boyfriend. Then she described her type and it almost matched me identically. My girlfriend then pointed to me as a joke and Lauren said “omg no never” and we just laughed it off. We hung out for a little more and my girlfriend wanted to go get some food from Safeway since I lived relatively close. When she asked I was doing laundry and Lauren was sleeping upstairs on my couch so my girlfriend just said she’d go by herself and I said okay. I finished up laundry and went upstairs to check on Lauren and she was up.