He laughs at her for squirming, meeting the writhes of her body with rocks of his, breathless as he drags his mouth from hers to kiss her neck, suck on the skin there. He doesn't wear a belt (and never quite got the point of boxers) but since his only answer to the hand at his shoulders is to roll them against her touch, Sokka certainly wouldn't be adverse to losing that part of his clothing.

And, not wanting to tickle her, his hands are in a similar spot a moment later, brushing the clasp of her bra.