The child in question is only 5 months old?
Hmm, I would say it's unlikely at the moment, if he drinks, that he will be allowed over night access just yet. He would probably be set up with supervised access first
He can be with as many women as he likes as long as he doesn't introduce each and everyone to your son, it doesn't make him a bad dad
Drinking doesn't make him a bad dad but could make him an unsafe one if he drinks when he has his son
Trying to kill himself doesn't make him a bad dad either, but he could be unstable.
If he can prove himself over a period of, say 18 months - 2 years with continuous and steady access I see no reason why he could not be awarded joint custody and bravo for him if he did want joint custody and really means it - so many fathers do not.
If I were you I would just wait and see if he actually goes through with it first by consulting his solicitor after all it oculd be an idle threat