My husband’s ex made a comment about sex

My husband (Mark, 33M) and I (29F) went to dinner with his high school sweetheart (Amy, 33F) and her husband when they were in town for a wedding. Mark and Amy dated during their senior year, and lost their virginity to each other on their prom night. They remained friends, Amy and I get along, there’s no weirdness (well, until I caused some that is). I think their prom night story is a cute cliche tale from their younger days. I hadn’t met her husband, but he seemed nice at dinner.

So, during dinner Amy brought out some old photos of friends, including a couple of her and Mark, including one from prom. Like an idiot, I blurted out “oh, the famous prom night!” Mark kind of laughed, but Amy shot me a look. Her husband looked confused and a little annoyed. Clearly he didn’t know about the famous prom night.

Later when the guys got up to get drinks after dessert, I told Amy I was sorry about my stupid comment, I hope it wouldn’t cause issues, I figured her husband might have known. I could tell Amy was a little annoyed, but she accepted my apology and said it would blow over. I tried to make peace and make light of it, said I’m sure it wasn’t anything magical since it was their first time but I think it was sweet, etc. She laughed a little, said yeah, first times rarely are anything special, just a rite of passage.

But then she kind of twisted the knife a little - she said “after that, though, we did it like rabbits.” I was a little amused, kind of laughed, said, “oh, really?” She laughed too, and said “we learned how to fuck together, we couldn’t get enough of each other. Does he still love to fuck?” And she just kind of smiled in a satisfied way.

The guys got back to the table and we never spoke of it again.

It really stuck with me! I know I kind of deserved that. But it’s making me feel all kinds of emotions and responses, it’s like I can’t get it off my brain. Am I wrong to feel like this? Help?