I think asking her again the second time is alright as long as it was respectful. Unless the person who was asked gave a firm response, I don't see it as "creepy" and I think it's fine to try again another time. However, in this case she clearly told him that she had a boyfriend the second time he asked which tells me that she was firm in her rejection. The fact that he went again after that just tells me he's arrogant. Like, unless he thought he could steal her from her boyfriend, I don't know why he would try again and that to me is pure arrogance. And the fact that he stayed outside her door the whole night is just creepy. I don't know about other girls, but I would have been scared if a guy waited outside my door the whole night. I would also be super frustrated that he's not leaving me alone.