A soft, involuntary whine slips out when John pauses his work, and Martin holds his breath for a second, releasing it in a frantic huff the moment John grants him the permission he needs. He struggles to get his trousers open and reach in without causing any real disruption, letting out a thin, strained cry when John bites down on a new spot, but finally, with a warm hand wrapped around himself, some of that tension slips away. He could just melt against John if he wanted to, but instead he slumps back against the wall, taking care to keep a bit of distance between them. He settles into a rhythm matched by his own short, shallow breaths, every exhale coming out as another plaintive moan or whimper. He isn't going to last long — doesn't want to last long, doesn't want to drag this out when instead he can have a swift release and then collapse into bed with John happy and warm beside him. But still he doesn't rush, lets himself arrive there naturally, the slow upward tilt of his head the one concession to that latent desire to push closer, to be held. Not yet; not 'til after.

"John—" he whispers, his breath stuttering in his throat as a sharp, telltale shiver moves up his spine. "Oh, Christ, I'm—"

He reaches out with his free hand to grip John's arm, gently holding him at bay as he half-crumples over on himself, gasping and shuddering until he's spent. He remains there a few seconds more until he leans forward and lets his head come to an awkward rest against John's shoulder, still curled over and breathing hard. "Mnh," he says, a start to something more substantive hampered by the inevitable wave of warm, pleasant exhaustion.