MfM with my gf into my first time as a cuck [first time ]

Our first experience was when we tried having a threesome with her ex fuck buddy kyle. He came over after we were at a club in river north and we’re dating for a couple years. We were out with a couple of friends and he hit her up and sent her a dick pic and he was rock hard and like 7in. So I said want to invite him over for a threesome. He came to my apartment and we all started fooling around. Tried to have a theeesome while he fucked her from behind and she tried to suck my dick. I couldn’t get hard and felt a strong urge to go sit in the corner of my bedroom and watch. She was like “babe are you ok” and I’m like no I’m good keep going. He came on her stomach and went to our living room to pass out on the couch. She cleaned up and got in bed with me but I could tell she was still so horny. I said babe if you want go fuck him in the living room and she asked me like 5 times if it was really ok. I said yes and she eventually did. I listened to her get railed from behind over the couch by him as I stood in the doorway out of sight listening and it was literally the hottest thing in my life to that point. I heard her cum and him cum all over her ass and came on the floor of my hallway. She waddles back to me and was like are you sure that’s ok and I said yes it’s fine. That’s when I knew I was a full time cuckold lol