Alphinaud gets railed by a guy twice his size (Gaius, Quintus, Ilberd, whoever) and the dick is so big that it presses on his bladder the whole time they’re fucking, until Alphinaud can’t hold it any more and pisses himself to his absolute mortification, bonus points if it’s one of the villains and they mock him for it while they keep right on using his holes (cis or trans Alphinaud acceptable for this prompt)