Question: how to know if your best friend's girlfriend likes you?
Answer: He's the only friend of yours that she likes. ... 
She always wants to tag along with you and your guys when she knows he'll be there. ... 
She dresses up when she knows he'll be around. ... 
She always compliments him. ... 
She has a pet name for him. ... 
She adds him on every social network. ... 
She inquires about his dating life.