I feel stupid for being mad over this..

I glanced at my boyfriends phone and realized one of his female friends contact had her picture attached. Only me and his mom have a contact picture. When we first started dating he took a picture of me and said “only the important people get a contact picture” I almost broke up with him for flirting with this girl and seeing her picture just really irked me..

I just saw it but I tried to ignore it. Should I bring it up or is it not that big of a deal. I know for a fact this is going to change my mood for the rest of the day.