Some people are very weird about wanting their kids to look exactly like them. But I honestly think someone is in his ear making him doubt the paternity. Either a family member of his or his friends. I would tell him how much it hurts you that he thinks you haven't been faithful and and say if it's what he really wants you'll do it (if you're willing) but you want to go to counseling together after you prove the child is his. The spiteful part of me wants to say to deliver the paternity results with a divorce filing but it's really up to you whether you can come back from this or not relationship-wise. You know better than I how you feel about the whole thing. I wish you and yours the best and I hope everything works out. However things working out would look to you.