[ The boy very much does not like being manhandled, BUT... he listens because this sounds serious. Maybe the other kid can't help the way he is. Maybe seeking "help" is dangerous in and of itself. Touma doesn't know his situation; he has his own to deal with, after all. His own secrets.
He stares on as Cain makes his request — no, his demands and conditions. It's clear that he's unhappy with the situation, but what choice does Touma have?
He'll rub his wrists, not feeling entirely clean about this method, but again: no options. ] Fine. How the hell am I supposed to arrange anything if I can't call you? Are you just going to find me?