What can he do??

I've been dating a marine for a year and a half now. One of my friends {not friends anymore} starting telling people that he was crazy , abusive & that he was starving me, saying I was fat. I never told anyone that because he's not like that. He never laid a hand on me , he makes sure I feel special and he never ever mistreated me. he is a really great & wonderful guy. Is there something he can do or can she get into some kinda of trouble for slander??