Giz...
Don't play this game with him. If you want to quit to be supportive or because you don't like or trust alcohol any more, good on you. But don't be manipulated. It won't make the difference in his getting sober. You haven't even said that he's indicated he wants to get sober. Your sacrifice is not going to inspire him. Don't make deals with the devil.
Hugs and Welcome.
Smoke