Yes, it is called "lust" ... when his eyes wander to another gal and he wishes he was with her instead of you, it could be a form of cheating.
I don't know. Talk to a therapist.
I'm not sure if this will help but does your boyfriend like your cousin? If you have faith in your boyfriend then even if your cousin really DOES like him, you know that your boyfriend won't cheat on you. If he really does cheat on you then all i can say is - you deserve better than that. As to how to tell ... I guess you can talk to your cousin about it? or you try to talk about your boyfriend to your cousin and notice her reactions and expressions.
Because he still has stong feeling for you still....talk to him
cause he still got her number and they talk more then they need to talk....
I would still be friends with them if my friend would still talk to me.
tell him she was a friend or a cousin and ask him to go out with you again .
If you still think of your ex-boyfriend and talk about him that means you ain't over him. If you continue to hate your ex that means you still got feeling there.
He might be more buisy than usual. If you are concerend about it then just talk to him. If he likes you still then he will tell you why.
well look for signs does he still talk hope it works out
because shes waiting for you to ask her out
If they flirt/ talk alot, you can check their emails/ texts, and if he is acting distant and uninterested towards you.
Does he talk about her a lot? Does he still talk to her? Does he keep anything that used to belong to her? Does he still keep pictures of her? Make your own personal decision when answering these questions.