I'd love to finish in her mouth once in awhile, but my girl seems to have an aversion to it, as have most of the girls in my past.
It's actually weird... they've all "said" that it didn't taste that bad and it was easier than they thought, but usually after the first time, they never do it again, and I feel like an ass for asking (I'd really rather not complicate the situation, considering she's sucking me in the first place).
So, a little sucky, then a little fucky. Everyone wins.