boyfriends 21st birthday

My bf wants me to be with him on his 21st basically to take care of him. I am not a drinker i cant stand drunk people. His plan forever has been to do 21 shots. He throws up on the weekends always which i dont want to be around so dont see him. Will i regret not being with him that night. I feel like i will try to tell him to stop drinking because im cautious like that. What do i do? I want him to have fun but dont want to be a burden. I feel like if i go i have to stay to make sure he is safe because ik his friends wont. Help!