He can say it was only a little bit and it was no big deal. Of course, he would say that anyway. But what he's missing is that the lies and him still feeding his addictive thinking IS a big deal to you. A little pot or a little alcohol. Same diffrence. For some people is wouldn't be a big deal. But he's not 'some people'. He is an alcoholic, which means he has an addictive nature. So it IS a big deal. It means he isnt emotionalky present or reliable. While he is in addictive thinking (which he will be if he is using or drinking -even a little bit, and not working on his recovery ) he will continue his Peter Pan thinking. His selfishness. His denial.
You're no bad guy. Just realistic and doing what is best for you and your family.
Please don't give in to his quacking,