my best friend is stupid

my boy best friend is so stupid. He is in love with a girl since last year but she clearly doesnt care about him, she ignores him just because, does not show any afeccion, gets angry when he talks to me, and a lot more, but he still love her, he even asked her to be his girlfriend, honestly i was shocked when i found out that she said yes. I dont like her. I saw my friend crying for her, thinking that he didnt deserve love, and im just worry about him. 

I hope that she changes, or that my friend realises that she isnt good for him.