

Boyfriend finds another women's skirt in his apartment
My boyfriend (35M), and I (25F) have been together for only 3 months. This morning while working he casually sent me a picture of a skirt that is NOT mine. After getting upset about it, he tries to brush it off. Then stops responding for hours.
Am I overreacting, is this breakup worthy?
I have no idea when or who it's from. I would like to assume it's from before me. What should I do?