I'm not cheating I only have girls as friends, nothing more than that, I'm never attached much
Your boyfriend might always think of something else or would be lost in some thought, or when you're talking to him you might see that his mind is not present in your conversation, and he is lost somewhere else or smiling and is not paying attention to your conversation, so those are the signs when a boy is cheating on you or is attracted to some other girl!
Well I would keep a eye on him, if you usually talk to him before you go to bed and he's not there he might be with a different girl, but god forbid that happening.