My buddy brings this chick into our fold, pretty flat chest but great ass and pretty face. She has a boyfriend already. Dude is being a total beta, sleeping on the floor when she stays over, making her dinner, etc.

First day I meet her shes sending me IOI's. I decide the best thing to do is act uninterested so she'll want me more, then I can start fucking her on the side. I get her snap and she snaps me first the next night, then every day for several days, sometimes double texting

Then all the sudden 2 nights ago her LTR makes her mad and she comes over, she's all affectionate with the other guy. She leaves and he tells us (me and another friend I came with) that she suddenly started being affectionate once we showed up but he doesnt know why. I decide it's because she wants me to be jealous and notice, figure it's all working, no problem.

Last night, she stayed over at his apt again. He fucked her 3 times. I'm pissed because that was my fuck and idk why she gave it to him. I thought that beta male shit would never get him laid and me acting indifferent would make her beg to fuck me??