“Oh come now, Koschei,” The Doctor says says softly, cupping the white substance of the newly-reformed Benjamin Pond Avatar and pressing into the belly, disappearing the unoccupied material into himself until there is no sign of swell. “It isn’t that bad!” his skin begins to glow, turning grey then pinkish, then finally the fair peach of his normal tone. “Has River got into hers yet?”
“Yes I have, sweetie!” comes the call-out from a darkened crèche across the room. “You should check on Borusa!”
“Why? Is Bimbo Smurf too old to dress herself? And how come you can do that to your Flesh’s morphic structure? We can’t control ours like that!” the Master yelps from the youngest Avatar model’s boyish lips, smacking the Doctor across the back of the Doctor’s leg, near the knee. As he touches the body, the flesh-like substance undulates slightly.
“Because this one…” with a snap of his fingers, the Doctor’s usual suit grows around his Avatar like a trick tablecloth, peeling backward over his bony frame. “… is double-routed.”
“And I’m supposing, my love, that this double-routing has to do with how many complicated biomechanical substructures allow or inhibit the energetic connections between the ions in the artificial substance of which the Flesh is composed? Yours, therefore, has twice as many bioelectrical microbridges, for some unknown reason that you will probably never share. Is that it?” River smirks, coming up behind him and applying her fingers to his bum, the better to pinch him with.
As always, he squirms like an eel in the hand, only… his reaction ranges –into- her touch.