On her

You know two things that should help you win. The first is that whoever makes the judge happier will win. The second is, through your past experience, exactly how to eat her out to the greatest effect.

You move Nathan other, crawling between your friends legs and asking up to her with big subby eyes “Ma’am, May I prove my oral skills through pleasing you?”

She smiles, her fingers running through your hair as she says “why of course you can.”

Having received permission, you lower her pants and underwear sensually while massaging and kissing up and down her leg. Once you were in the clear you worked your way to her pussy, kissing around as your hands squeezed her thighs and hips. You then worked to her clit, licking and sucking playfully before building a steady rhythm of licks. You knew her tastes, quite literally, and knew to get the most from her was to start with teasing but to have a steady unbroken rhythm for the main show.

You keep up the steady licks, hearing some light moaning and her hands grasping and yanking at your hair. You figured you got this in the bag... until Nathan starts playing dirty.