Why do you keep asking? How do you know he isn't telling the truth? How about asking something else, like 'Who are you voting for for president?' or 'How about those Red Sox?'

If he is spending time with you, why do you think that he is after some "new SKINNY girlfreind"? Has he espressed interest in SKINNY women? Maybe he likes normal women like you? I think that most men don't find skinny women attractive.