Is it cheating? Thinking of cheating?

I've been with the same man for three years. He's a great guy, on the surface at least. I've gotten the vibe over the past year or so that somethings been up and although I know its a big violation of privacy and that you only find what you're looking for, I got into his myspace. He's done the same to me so I don't really need the guilt trip. The problem here is the several messages telling other women they are "hot" and one in particular that she has a "smokin' ***". I've never known him to act like this in front of me. Do you think he's cheating?