Why does a boy delete messages about girls in his space? (The premise is that they are classmates, good friends and once bosom friends. ).

If that boy were me. I consider from two points:

First, I hinted that I liked this girl before, but she refused. I feel ashamed, so I think it's better for us to draw a line under this circumstance.

Second, now all boys have girlfriends. If other female friends leave messages. Or a little ambiguous language will make your girlfriend unhappy. So delete it.