I've always hated the "I was born this way!" excuse for poor behavior. I want to say to them, "There are people who were also born that way who manage not to engage in whatever you're trying to get out of being responsible for (especially when you're saying *all of humanity* is like that, which incidentally I'm not sure I buy in this case since there's a good arguement that it is much more related to how our culture approaches monogamy, but I digress). Accept that you, personally, fucked up and deal with it like a fucking adult already."