It was meant to be reductionist. And made you cough up circumstances that you hadn't (like who dumped whom).

Well, if I was BF2, I would feel used by you if you dumped me just to go for your ex, and if I was your ex and found out about everything, I would still feel weird. One way or another, you should break up with BF2, as it is unfair on him if you just keep comparing him to another guy. Then check if BF1 is available.