Don’t apologize just because you think that’s what she wants to hear. If you’re going to apologize, make sure it’s only because you were 100% wrong and you’re going to change your behavior to prove your contrition.
Stop being a pussy. Man up. “I’m sorry” should definitely be in your vocabulary, but don’t use it as a crutch to get her to stop complaining about something you’ve said or done.
When she accuses you of wrongdoing, think about what you’ve done or said, but also think about what she’s saying. Maybe she’s right. Maybe you were a bit of an asshole in front of her parents.
But then again, maybe she’s just complaining to see how you’ll react.
Stand by your words unless they were idiotic. Stand by your actions unless they were embarrassing. Dig in your heels.
Girls can’t respect a man who apologizes too much, but they sure as hell respect a man who apologizes only when he’s genuinely wrong.
If you’re wrong, own it.
If you’re not, stand your damn ground.