what does he do?
Of course not. It is a possibility, but usually it is a more friendly gesture. If you have enough male friends, you would notice that they do it without trying to imply any romantic interest.
One of the signs is you friend is trying to get you to break up with your boyfriend. Also when ever you are alone together she comes in and interups you. If she is always laughing and "acting dumb" around him that's another sign. If she's trying to always hang around him and his friends that should be pretty obvious.
well she may not pay much attention to her boyfriend and is hanging out with other guys and maybe flirting with them.
If I was the girlfriend, and I know what's going on, I will talk to this girl and ask her what she is trying to do. I will ask her if she knows that the boy she is trying to flirt has a girlfriend. I will be civilize and calm and be professional about talking to the other girl. I will also tell her how will she feel if it was her boyfriend that's being flirt by another girl. Then I will ask nicely to stop flirting with my boyfriend.
no hanging out
maybe theyre trying to act cool
you know if he keeps doing just to get your attention, and if you get mad and upset then it means your jealous
If a boy likes you,he'll probably be flirting and waving constantly because he's trying to make a good first impression.
it means that hes trying his best but he wants to just be friends
If you are starting to like your friends boyfriend then I would recommend not trying to get into any relationship with his/her boyfriend you might be rejected and either way you will more than likely loose your friends relationship.
It means he is trying to fit in.
Explain to your friends how you are feeling, and if they are true friends, they will respect you and your relationships.