"You t--" he starts, but breaks off with a gasp.

Oh goodness, she's really good at that. He's suddenly glad the shower is muffling the sound, because he can't physically stop himself from moaning as her mouth moves around him.

As she takes him deep, his hand (which has slid to the back of her head) tightens in her hair, before he quickly lets go to avoid tugging at her hair.