Help :/

I think my boyfriend is gay. I don't know how to bring it up. I'm not mad or anything but I want to know. If he is then we'll just be friends that help get each other laid lol so I'm not mad or angry or even disappointed but I've had this feeling that he's gay or at least not sure about himself for a while now and I really just need advice on how to ask or bring it up? :/ thanks.