first rule for when you're in a hole.
Cruz is an attorney. By all accounts a very, very good attorney. Would he allow a client of his to meander around shooting off his mouth? I don't think so.
All he needs to say is, "I don't know who started this silly story. It's not true. Let's move on."
Nothing he says here would hold up in any court of law.
Personally, I don't care if he cheated on his wife. I'd be more surprised if he hadn't.