Jon takes note of Martin's reactions, his uncertainty and near panic of before giving way to curiosity more fully now. It was funny, he never felt any particular urge to be tactile with anyone but this was... nice. Martin giving him the time to come to terms with it himself, letting him explore, being so god damned understanding about it- his chest felt tight for some reason. It was certainly something like fondness.

When Martin moves over Jon rests his hand on the side of Martin's neck, leaning in and kissing back with the same attention to trying to learn the ins and outs of this as before. Look, if he was going to kiss someone he was going to learn how, ok. Besides, Martin seemed calmer than he had all evening, or at least less upset.