I know that feel, sis.
Thinking about it, how many movies are there where if a guy likes a girls and she's clearly not interested, if he persists, she'll eventually fall for him? Doesn't work like that in real life.
they're like, "aw come on, dump your good looking, gentlemanly, funny boyfriend for me and we'll paint my Warhammer figures together."

No offence to any warhammer fans of course. Just using this as an example...
I'm gonna guess this guy is one of those "OMG she shuch a *****!1!! friend zoned! *****! Why won't she go out with me, I'm a nice guy!"
If I were in your shoes, I'd give him a bit of advice and tell him to stop being so desperate as it really freaks girls out. Blocking him is a good idea, although that would add to his bad social skills, I reckon...