AITAH for acting jealous on my gfs memory

I love my girlfriend and we trust each other. Last night when we were talking casually I told her that I know how to waltz. And she said " haha in primay school my teacher partnered me with a boy who drew all the attention of the girls, they were falling for him and and girls hearing that he will also be in the dance they used pink lipsticks and I got to dance with him" The context itself is pretty normal imo. The thing is she recounted this memory in great detail with emphasises like "All the girls wanted him but she got to dance with her" after I started acting jealous we had a small argument. Am i the asshole acting this way?