i think it’s one of those things like – literally the relationships are just different. that’s really it, you have different relationships with different people, it’s never the same love twice. he has been married to river, we know they’ve been physical before, so there’s a level of familiarity there on a separate level than he’s had with clara. i absolutely am of the opinion that his feelings for clara are stronger (i ship both so this is honestly objective) which i think is one of the reasons he tried not to be tactile with her for so long. and obviously it’s river, she’s a flirt, she’s sexual, he probably wants to impress her considering she so overshadowed him as eleven and now he’s at a point where he can turn the tables on her. that’s what i think about it anyway!