Cassian puts his jacket on and takes it off multiple times in this movie, wholly unselfconscious.

Jyn, the stressball she is, grows very fond of watching him change clothes and finds it relaxing.

Cassian is at first a bit embarrassed and then become confuses when he realise the effect it has on Jyn when he's not even *actively* seducing her.

Then of course he actively seduces her.