How Do I Get My Friend to Not Drink and Drive?!?!

Hello, im a 21F. My friend (21F) and her boyfriend (21M) are about to go out soon. They want to go to a bar. I asked if they had a DD, and the boyfriend said he was going to be the DD. I asked if he would drink, and he said yes. I said that is unsafe and he shouldn’t do that. He said that he used to work in a bar, and he has an extremely high alcohol tolerance. He said that it takes about an hour for a shot to metabolize in your body, and he was going to take 2 shots when they first get there. He said that he will be fine to drive, because the alcohol will have left his system already by the time he does start driving. He also told me it takes about 7 beers to get him drunk.

These are the same people that went out yesterday, during an active tornado warning, because they wanted to go to the pool. My friend and her boyfriend are planning to break up, and they want to live up their last week together as much as possible. I don’t know how to drive, so I can’t be their DD. What do I do?! How do convince him to not drink at all? Will he really be okay if he takes two shots, then drives 2 hours later?!