Should I delete it

So my bf told me to look up something in his calendar n I saw a date saved from years ago from his ex I guess or some girl. Idk why I got super mad I think that was the day they had sex or something but idk if I should delete it or just leave it. It really bothers me but I don’t wanna tell him 😭 he probably forgot to delete it should I do it for him.

Update: this is what it said “Emily came so much lol.” I used a different name but I’m pretty sure he meant it in a sexual way. Also he’s always said I took his virginity away n I’m the first girl he’s ever touched so...

I’m asking him just texted him I’m so nervous.!! I decided I’d rather ask n see what he says n see if he chooses to delete it himself or not