Am I overreacting

On vacation with wife- 10 year anniversary. I go to bar wife talking to guy at table next to us. I didn't think anything of it. She then says she has to go to restroom, notice across the bar she is talking to him on the way to restroom.Then she comes back to table starts singing with guy during a song. I turn my back to her and she immediately starts asking what’s wrong. I get out of situation and close tab at bar. I tell her we will talk about it somewhere else and she knows what is wrong. Once outside I calmly explain what I am feeling and what I saw- in the past would have reacted crazily. Her first response is he is gay. I ask how do you know he is gay, did you ask him. She says no, I just assumed he was gay. How do I handle this? Was I wrong for being jealous? Was I wrong in trying to have a conversation and then be in shock when first response is he is gay? Did I overreact? Is she playing me?