Crowley could behave, but he certainly doesn't want to. All the same, he'll take a sip of his drink and relax his hand on Aziraphale's thigh, not furthering his misbehavior, but not continuing onward. After all, he doesn't actually want to embarrass the angel.

"What do you think about taking a ride to the beach next?" he says, moving to the next glass. "Or a walk, if you'd prefer. Go for another swim?"

Crowley secretly also wants to see the state of this ocean as well.