I have a boy problem..please help?!(:?

SO i like this guy and he likes me,but one little problem..he has lke a girlfriend but she wont really let him break up wit her.shes kinda crazy.but last night we went to the mall and had a AMAZING time together.And his gf txted him saying "I know things are complatcated now,but u can see anyone u want to.." (there not rlly together) so he broke up wit her last night and she was crying and all and he txted me saying he felt bad cuz she is crying but he dosnt like her anymore.So right now hes like "dating" her but they r not even a couple!! So what do i do? he likes me alot! i like him,he does not even like her..should i just leave this sitaution or no..? please help :)