Many politicians wear religion 'on their sleeves'. [=show their religious beliefs in a very open way]
The mayor's critics were 'laughing up their sleeves' when news of the scandal was first reported.
He 'wears his emotions/heart on his sleeve'. [=his emotions are easy to see]
(..) Take your mask off, quick. Let me see you. That's deep. Right. And this one here- You're from the rd Precinct? Let's open up his sleeve a little bit. All right, fine. Put it down. This one. You stay there for two minutes. I'll be right back. Let me put the mask back on. (..)1994 Léon: The Professional