should i let my father see my baby?

i’m having a little girl in May. my dad was really upset but also excited when i got pregnant (i was 17, a few weeks shy of my 18th birthday) but despite his excitement he let his wife kick me out because of my pregnancy. his wife has cheated on him and they have been really on and off, and he has been relapsing on meth. (he was 5 years sober at one point). so it’s safe to say he is not emotionally stable. this isn’t my first experience with addict parents, as i pointed out these are relapses and not new experiments. my own mom struggled with meth and alcohol addiction so this is something i’m used to. i know the whole “maybe this time they’ll actually change, maybe this time they’ll ACTUALLY stay clean,” mindset. and i know that an addict had to want to be clean for THEMSELVES, you cannot make them want it. i’m know my dad wants to be sober again, but i don’t know if he’s willing to work for it. the one and only reason that he will stay sober (if he does) is because of my 4 year old little sister. she is what makes him want that for himself.

my dad is now 11 days sober, and i think that if he stays clean then i don’t have a problem with him seeing our daughter. (one more relapse and he won’t be allowed to see her). but my SO says he doesn’t want my dad around the baby at all, seeing as when the baby comes my dad will have only been clean for less than half a year. i don’t know what to do. my dad is excited about being a grandfather and i don’t want to ruin his experience, but then again he kind of ruined it for himself, because i made it clear on christmas that if he didn’t get clean he won’t be allowed around the baby. my SO also has a say in this, of course, he’s her father, and if he’s not comfortable with my dad being around the baby, then what can i do? it’s not just my decision, i’m not a single parent. i have no idea what to do about this.