Is it wrong that I don't love my stepdaughter as much as my real one?

I can't help but feeling a bit angry about this. Children are not there for YOU. You're stepdaughter's purpose is not to please YOU or to take care of YOU. You're there to take care of HER. What's so difficult about that? '' she's a constant pain in the ***'' . Seriously ? You probably can't help it, but trust me, you sound like one hell of a bad stepfather to have. Do you have any idea how easily you can scar children for life with an attitude like that ? Loving your own daughter more, it depends on how long you are this girl's stepfather whether that's wrong or not. If you have been for like 3 years, then yeah, that's wrong. It should change overtime, anyway. A stepdaughter versus real daughter situation is always tough I guess, for them anyway, sisters that have 2 parents in common already often feel like they have to compete, let alone these two ! But don't be like this !