Lets not get caught in the Society or this Forum’s ‘excuse sympathy of ADD/ADHD vs failed practical teachings of a parent’ genre because it is accepted by people on this forum to blame a symptom and not the Root.
It is not acceptable behavior for any adult to fail to participate in a child’s life regarding responsible social behaviors (i.e. washing hands, no bird poop on couch, no bathing practices, etc.)
The adult here, the Father you married, is the only one who has the responsibility to change the ‘learned’ behaviors provided to his children by his Actions and Inaction. If he tossed this to you to do, or He belives all this is ok, you have much more of a problem to content with than trying to change a persons bathing habits.
And do not what so ever lay down or ignore the fact you are a step-mom, which is like bringing a goat into a lions den and expecting it not to get eaten. I know, I was a feral child when my step-mom came into play, and i never ever liked her.
In the wild, a female lion normally kills a stray lion cub not her own. Children know this inherently.
I believe your goal is to do one or both of two things:
1. Hammer him (the father) to make consistent behavior changes with His children (not your children), or
2. run from this as it will only harm you as all your statements are extremely unhealthy for you.
Love them yes, but like a Teacher at school, let them go home where its the Fathers responsibility to make change.
As these Social changes occur, the ADD/ADHD behaviors will show more predominantly.
Highly recommend Testing for Him and the children.
Highly recommend individual therapy for Him and the children.
Like it or not, truth must be presented.