"Ta," John snickers out, amused, and then tilts his head down a little to make his mark down Q's neck. They should both probably just get matching tattoos for how damn often they seem inclined to prove the other is taken and no one else should be touching.
Shirts? Fuck shirts. John's fingers aren't lacking dexterity at all when it comes to undoing buttons, proving that he is both determined, and better at drinking than most.