What would you do if you found out your boyfriend is biual?

My friend thinks that her boyfriend is because lately he's been talking and walking with a twist in his hips. He's also holding his hand like woman..instead of him putting his hand down he's holding it up like a lady would do when she's carrying a purse. She is so paranoid because he never use to act this way before around us. Now he has this friend he talks about all the time and when we met him..well he was kinda standoffish... like a girlfriend would be when her boyfriend was speaking to another woman.hmmmm What do you think? What would you do?