Martin twitches and gasps beneath him, and John mentally logs his latest maneuver as a success — a conclusion that briefly falters in the uncertain moment between Martin lifting his hand and him gripping the back of the couch. Novelty is potent, but it doesn't always pay off, and there was always the chance that Martin might not appreciate such irreverent manhandling (and might answer it just as irreverently, with a well-earned swat). But it seems he just needed to brace himself, and John suppresses a smirk before shifting his focus back to the work.

Martin's right side is variably flushed and marked from John's attentions, but so far, he's left nothing that will last. That ought to be rectified, he thinks. If this is all a reminder of how much they mean to one another, it stands to reason that a lasting mark or two would both extend and cement the lesson.

So. "I've got you, love," he murmurs, pairing the tender endearment with another cheeky squeeze of his hand. Letting his thumb settle into a holding pattern around Martin's left nipple, he adds, "Hold on tight." Then he bites down on the soft roll of flesh where Martin's chest meets his belly, pulling it between his teeth firmly enough to bruise.