While his masturbation is an issue that should be addressed. I agree with FXDB, the more serious issues lie with his communication on FB. Why is he seeking out attention from other women? You put this on the other woman for asking the questions, but it is a 2 way street, he responded and asked her the same questions. His responses were correct he said he would never cheat on you or claims that he said that (of course he deleted the conversation) but the bottom line is that he participated in the conversation, and did not put a stop to it as soon as it crossed the line. I view his masturbation as a separate issue.