Originally Posted by Acetylene

Offer for her to finish you with her mouth. If her desire really is for you to come, this will be a perfectly good solution (offer to wash first in case she doesn't like how she tastes).

If there's something else going on, though, like selfishness or some sense of propriety, she will refuse this suggestion. In that case you'll ned to find another solution, depending on what her real motivations are. Maybe you can try using lube to fix the dryness problem, or you can give her a longer break during which she can keep you ready with her hands (not exactly a triathlon, don't let her say she's too sleepy). Or, try different positions and find one you like better than she does so the scheduling works out better.