Narcissists often project their own flaws, insecurities, and guilt onto their partner(s). I would agree that ‘once a cheater, always a cheater,’ since narcissists will always come up with some kind of excuse or justification for their behavior, inevitably followed by massive blame-shifting. It’s anecdotal but every single partner I’ve ever had has cheated (I’m 36 and have plenty of experiences, both casually and in LTR), and each and every one followed this pattern of behavior…