Why do i have dreams of my man cheating on me ? ?

When we fear something, we attract it to our subconscious mind, to figure it out, or to find an answer.  That is what is happening here. You are so worried that your man is gonna cheat on you, you even dream about it.  Dreams don't predict the future.  But they do make us aware of what our fears are al about.  Unless you have real physical proof of cheating, I would relax and be happy to call him "my man!"

You must have a reason for thinking this way and if your sex life is nonexistent it maybe because you refused his advances too many times and he's lost interest. Consequently, it's on your mind and you're having dreams. 

Try making the advance yourself by having a nice show, doing your make-up and wearing a sexy nightie. And be adventurous in bed.