Like your mum said, pray for him. Let God change him because you can’t. None of us can change anyone, threatening to leave will only make things worse. Stand by him. Pray and fast for deliverance from addiction.
If you're that concerned leave. Clearly you're not happy and feel some kind of way. Before I had my daughter my bf drank every day however once we had her he stopped because he knew it was what I wanted and best for child. He now only drinks on special occasions and random weekends
If you’ve expressed your concern and there’s been no change in actions, then that just tells me there’s a lack of respect there. Explain if you haven’t already the type of imagine it will set for your children and what type of role model he will be as they grow up. Ask him how he wants his kids to think of him. Let reality set in and see if that can encourage a change. If not, then you have to question his loyalties. Although, it depends if we’re speaking about 1 beer with dinner each day or if he’s day drinking and getting drunk every single day.
If his lifestyle has changed to one that you don’t want in your life then leave! I would try talking to him & getting him / you both therapy to get at what is underlying, but unless he is anting to put work in it won’t stick.
You don’t need ‘enough’ grounds to leave a relationship. If you are not happy and have tried working at it, then leave. Only you know if there’s something to stick around and worth fighting for.
If he's attentive and loving and trustworthy, don't leave him. You can call Al anon to see what they advise. My husband drinks beer almost every day and gets buzzed. I always talk to him not to have that many. He has two or three but double strength. He sometimes listens to me. I don't leave because it's not that bad. And he's responsible as well. I once called all recovery help places from his phone and added his number. They started calling him back. It was kind of funny. I tried it all. And will keep trying. Pray as well.