Can he really tell if I was cheating?

My husband told me once that he can tell if I was cheaten on him and that he could also tell if iwas haveing it with someone can he really do that my hubby is a lot older than me and if he can tell he hasnt sayed anything to me

Why are you so worried about it? Are you being unfaithful?
And yes, there are a lot of signs when someone is cheating. I've been in that situation and I could totally tell, its easier then you think.

Yeah, my boyfriend can tell also. Not that I'm being unfaithful but if I'm just talking to someone casually he would find out about it

Body language comes out different when your not thinking of just him, and he can tell the difference :P

I can tell when OTHER peoples girlfriend's are cheating on them, I'm really good at reading peoples body language, not sure why, just good at it.

Well it sounds like you are cheating on him which isn't right. He could tell the change of attitude or body language.