Early on it was tough. She told me my little dick gives no pleasure so it deserves none and I couldn't argue with that. She said if I wanted to show my dedication to her then willingly not cumming anymore would make her the happiest, so I agreed to it.
About a month later she caught me jerking off and got really upset. When the smoke cleared she said if she ever caught me doing it again she wouldn't let me clean her anymore. That did it for me. I have not came since.