[Indeed he does... and at least this time he's mentally prepared. He also knows by now that Goku doesn't seem to have much in terms of food preferences, and thus simply walks up to the counter to uncover the first cake that happens to be there (a chocolate cherry cake).]
You may have a maximum of one slice before eating something of actual substance. [Sebastian will cook something. Look, he does nothing by halves. If he's going to feed a child, he'll feed the child good. However:]
After that, I am indifferent to how much cake you consume. [Just don't come crying to Sebastian if you get a tummy ache.]