Feeling needed isn't sexist, if you couldn't drive and needed your girlfriend to drive you around, there's nothing necessarily sexist about that either, and it might make her feel needed too.

If the reason you feel needed is because she's a woman and you're a man, as opposed to being because you can drive well and she can't, then it's sexist.

So its only sexist when you try to say out loud that you're better than her at something?