L4A I think I was cucked, please let me know though [cuckolds perspective]

I was at a party and my ex was there. We were both newly single , and not seen each other very much over the summer.

She wore a semi-see through dress , kind of like crochet style, with a tiny purple thong and bra. I’d seen her in it a few times when we’d occasionally be in the same spaces. Also at the time she lost some weight but her ass stayed big.

We got to talking just catching up etc as we didn’t know many people there. We kind of were stoops near a table and a doorway.
There was this one guy would walk past behind her and hold her hips and push up against her everytime. It was slow everytime and his hands weren’t light they clearly grabbed , kind of low but not fully on her ass. Couple times out of 4/5 he’d turn back and say something small and random, but stop right behind her to say it to me then move past.

Then my ex would say “did you see that?” each time, I suggested we could move but she said it was fine. Each time I think to exaggerate she’d let herself be slightly knocked forward so slightly bent. She made eye contact each time, then told me after he’d been touching her leg and thigh when they sat talking before I got there.

(Edit) feel like I should just be honest and admit it turns me on when I got home that night. And that I could see her nipples got hard clearly. I’m probably a little embarassed to post this even though it’s anon. DMs open