Add user to a secondary replica in SQL 2012 AlwaysOn

I want to add a new AD user to give access to the database that is in the Always on availability group. So here is what I did:

1. Added the AD user in the primary replica  & gave access to the db

2. Then added that user on the secondary replica. 

But that user is not getting synchronized on the db that's in the secondary replica. 

Also the master db is not set to be synchronized. Please let me know what I am missing, so that the user can be added to the db on the secondary replica.

Thanks.

sqldev