Partner has a season football ticket. If the home match starts at say 3pm, he will go out at noon or 1pm, and then come home at 8/9/10pm.
Tonight it was 10:30.
He came into our room, clattered about getting undressed (we co-sleep with DS and if he's had a drink he sleeps on the sofa). He was so drunk that he fell over and instead of getting back up he just stayed there on the floor and fell asleep. Snoring loudly and clattering about between our bed frame and the dogs crate anytime he tried to roll over. 
Tried to wake him several times and he'd just go back to sleep. Baby wakes for dummy and he lollops half his body onto the bed, then throws his head down whacking it onto my legs as he lays down.
I've come downstairs with our 12m old and we are now on the sofa instead of him.
We've had the conversation before that I won't put up with his drunken knobhead behaviours long term. I don't want my boys thinking it's normal and OK to be rolling in so drunk you fall over. He can't have a couple after work. He can't have just a few at a friend's wake. Match days seem to be get pissed days.
My trust of him being able to go out for a couple has long gone, and I'm pretty sure my respect for him on this has too.
I'm so mad and sad. I thought I'd finally found a good guy but this is the thing that will break us despite everything else being good.
I'm not afraid to be a single mum, I did it fine before and would again, but how would I even begin to THINK about making such a massive, family shattering decision. 
I'm exhausted anyway as baby is an awful sleeper, so I might not pop back to thread until the morning if can manage to nod off, but I needed to get this off my chest and hear some mn wisdom.