I believe everything should be open and crystal clear in a relationship. Hiding your text, call logs from your partner means you are not honest with him/her. If you are arguing for a password, the other person might feel cheated so there’s no harm giving a password to your other half if you are honest. Loyalty also needs proof… is it worth it to fight for a password? Even if you have a password on your phone, your partner should know it. For a healthy relationship there should be no barriers of passwords or anything else.