My best friend is madly in love with my teacher , but he is not that interested in her . She is really sad and I ca n't watch her suffer like that . Since he was my teacher , I ca n't talk to him for her -LRB- if I do , it 'll be like insulting her -RRB- and I really feel helpless . What should I do to make her happy ?
Will a guy feel sad when a girl whom he has been dating with leaves him ? He does n't love the girl , but wanted to sleep her ?