Opinions/Advice!

I like this guy who likes another girl. He knows I like him and so does the girl. I don’t think the girl likes him and she never has a clear answer. If she liked him she wouldn’t say I can have him and she should have a clear confident answer. When he thought she didn’t like him he was really upset which made me sad due to not liking seeing him sad. He has expressed to me the fact that he would change so she would like him and all this other stuff that isn’t healthy. There’s nothing wrong with him, he just wants her to like him so badly. I know he’s gonna get hurt and I don’t want that to happen. I told him he’s perfect the way he is, but I know he doesn’t care what I say. Opinions?