[MFF] the time I watched my girlfriend have sex with another woman

I (28M) met this “other” on Tinder. She’s a cute, slim, young (21F) brunette with beautiful brown eyes, 32B cup breasts. And a nice round bubble butt. She was interested in our polyamorous relationship. I’ll call her “Megan”

I described to her the threesomes we’ve had and the various kinks we do and our side FWB. I wanted this girl, but she didn’t want me. She wanted my girlfriend.

The night came after the three of us had drinks. “Amy” my girlfriend (F21) a short blonde haired, blue eyed, 34C Breasts led us both into the bedroom after shots of whiskey.

It didn’t take long for them to start making out. Even less time for the clothes to come off. At first I just wanted to watch. We’ve had threesomes with other women before, but I’ve never seen Amy fuck another woman before. I start fantasizing this Tinder girl, as a lesbian slut that likes to hit up couples for easy sex with women from men who fantasize sharing there women. Men like me.