I applaud the guy for confessing all that and taking one for the team, showing how girls can be dicks just as much as guys. But it also sounds to me like he was infatuated and clueless, and possibly still is, and she's happy to take advantage of that. She's still a dick (or more anatomically correctly, a cunt) but he did make it pretty easy for her. Three years of this shit and he still feels wounded. Time to move on, dude.