Bit of background, been with my GF since we were both 17 so hadn’t been with anyone else apart from each other before. But 5 years into the relationship and I started getting attention from another girl and eventually got a few hand jobs and blowjobs before fucking her fully.
Cheating on my girl then happened on the regular for about 9 months before I started to float the idea that we bring a third person into the bedroom with my girl and me. Even suggesting we get her another cock to play with or I watch her getting fucked. She even agreed to a threesome with another girl but it didn’t come to anything.
So fast forward a year or so later, I’ve stopped fucking this other girl. My gf is on a night out on the town with a few of her extended family, while I’m at home. Her cousin brings his wife along to it who also gets her brother to come drink with them to. This guy is a good bit older than us, like early 40s, keeps in pretty good shape, very confident, can tell he just fucks women regularly and just leaves them when he’s had enough. Seemingly they hit it off really well and she starts to get more secretive and distant, not answering calls or texts as quickly when we’re not together, not being as available as much as she once was.