There are many things about ex-boyfriends in my girlfriend's qq space. Should I ask her to delete them?

A really mature man won't let him delete it. The past is about the mood at that time, when you didn't appear. All you have to do is be kind and tolerant to her all the time. In fact, a girl can't help comparing the present with her predecessor. You are good enough to make her forget the past, so why bother and unhappy about it? Cherish the present, as long as you are serious, responsible and tolerant of this relationship, the other party will feel your sincerity. The past is only the past, and she will be more grateful for the present.