It's more 'teasing' in the 'Phillip still has a hard time not being a bit of a brat', so there's very little Gustavain would need to respond to it with, the result more playful than trying to get any kind of rise out of him.

His shirt is definitely soaking, but the solution is just to get rid of it, which is hardly a disaster. He'll linger for however long Gustavain wants to soak, mussing with his wet hair or possibly trying to work out a tension in his neck or shoulders, depending on how relaxed the man seems inclined to be.