Coparenting-need advice

My ex and I do not get along at all, there’s either a sexual tension on his end or a fiery hate, I somehow have remained neutral the entire time. His gf has been in the picture since apparently we were dating which we only dated a few months and broke up a week before finding out we had gotten pregnant. It’s been a long road, he has an alcohol issue and I fought like hell to make the courts see it but they wouldn’t so now we have a reserved court ordered schedule, the gf and I have a pretty good relationship now. He’s extremely lazy and passes the buck of his whole 6% responsibility to her unless they are at a gathering or something where he is showing off how “good” of a dad he is. He started having her do exchanges when our son was probably 3 months old (Now 11months) but has slowly removed himself, which is fine for drop offs I guess, but he now had his gf do the pick up. I nosily made sure he was in the car, but it’s not something I’m comfortable with. I don’t know her super well, shes not my sons parent, and I have major anxiety about someone taking him away. I think his father should at least be present for the exchange since after all it IS his time, not hers, though she cares for my son entirely while he is there. Should I bring this up to her or both of them or do you think I should just let it go? I don’t want to ruffle feathers but also know that the more I let go the more he will try to run with, like sleeping in with a hangover and having her come get him or something, which makes drinking in excess more convenient which I do not want and I am to be monitoring his behavior (per the judges order) kind of hard to do when he’s not present..