In the end the choice is yours and YOURS alone. Not every person is the same. Perhaps he just had a slip? It happens.
That being said, he'll never be sober if he's doing it for you. I've been there. I quit for my ex-girlfriend several times only to hide my drinking from her -- too bad she had a key to my house and came by while I was at work. She founds dozens of empty beer cans stacked up on my coffee table. That was all it took. She's gone now and I'll never get her back. I lost her trust. It wasn't until I TRULY wanted to quit for me that I was able to do just that. Hopefully -- I'm on day seven today.
Good luck with this. Keep us posted...