we have a saying around here:
quit going to the hardware store for a loaf of bread.
you KEEP going to your AH with everything, telling him things over and over, trying to get him to see the light, and time and again what has happened....?
nothing. your words aren't making a dent or a difference. you might as well go have a heart to heart chat with a pine tree....it will certainly be more engaging.
you two are now living APART, but only by the address. this would be a very good time to work on detachment and lessening the dependence you have on him.
your husband behaves in ways that are wildly inappropriate in front of children. how on earth a six year old knows what pictures anyone has on instagram boggles my mind. but the fact that a first grader is now using the word BUTTS 20 times a day, KNOWS that his father takes pictures of random women's backsides and then posts them is moving into very dangerous territory. your AH has some SERIOUS issues apart from substance abuse.
he also has you under his spell. and it's time to break that spell. quit worrying about HIS feelings, HIS thoughts, or what a "private" person he is, cuz that is pure BS. it's his smokescreen. it's his way to throw up an illusion that keeps you off guard while he then does EXACTLY what he wants with absolutely NO concern for how it might affect anyone else, including his children. i personally wouldn't let the man "watch' the kids.....dude has some sick thinking and has no business being an influence on children.
please from now on, if your small child comes to you and shares HIS impressions of his father, or his teacher, or whatever, don't immediately run to AH and give him a verbatim report. you unknowingly violated your child's trust in you.....and you cannot be sure that he won't suffer repercussions from his father now. your child needs to be protected, not continually thrown in the middle. and he truly does need some counseling NOW.....before he begins to act out. this could be things like bedwetting, getting in fights at school, hoarding food, being aggressive with pets. HE is where your focus needs to be.