AlwaysON Security User Mapping

I have a new security role so I added a new login and then setup up the user mapping for that role on the primary. But on the secondary after I add the new login, I can't see the db in User Mapping which I assume is because it is one of the AlwaysOn DBs. But how to keep the security in sync then? Does this happen automatically because the DBs are synchronized. How do I check?