Phillip's glad he does, because Gustavain's entire life would probably be more needlessly difficult if he didn't accept it from someone. And, on the selfish angle, he's glad it's him.

He will draw a bath, just because from a comfort angle that sounds more relaxing, with what oils he can find nearby. He won't join him in it- it's too small for that, but he might sit behind him on the edge, toeing the line between teasing and genuine care to help get his hair suds up.