How would you feel about this? - Is my husband cheating on facebook?

Cheating is not a physical act. Cheating is the intent, the thought, all the actions and the attempts at being intimate with someone other than your spouse. In my opinion, your husband is cheating on you not with one person, but with several. How disrespectful and totally insensitive of him to say that they are just "pictures". They're not just pictures. He knows their names, who they are, where they live, what they like and dislike, etc. I'm sorry you have to deal with something so painful and demeaning.