I agree with davidswife, Regrets. Don't believe a word he says. My W looked me in the eye many times and denied she was having an affair. She even denied it to her friends, family, and IC. Guess what? She was having an affair.
People having affair ALWAYS lie. So if he really is cheating on you, his words mean nothing right now. I know that hurts (it nearly killed me to know that my W had been deceiving me for MONTHS), but it's something you need to accept.
When a spouse's behavior changes suddenly, it's almost always because of an affair. They get hooked on the happy happy affair brain chemicals and they become a different person. Almost like an addict.
Me: 33 WAW/MLC: 33 M: 4+, T: 10+ Separated: Nov 08 A#1: Oct 08 - Jan 09 (exposed and ended) A#2: Feb 09 - ? 1: http://tinyurl.com/mrmistakes 2: http://tinyurl.com/ckch9t 3: http://tinyurl.com/stillwaters3