Unfortunately I found out that the guy has been flirting and hitting on a thousand girls online (one of them actually accused him of sexually harassing her; it's a long story). I feel like an idiot for believing his cheap compliments and sweet talk.
I'm very scared that men I date will pretend to care about me, then use me and ditch me. If this has happened to you, in hindsight were there any red flags or clues?