Been dating my boyfriend long distance since January of 2014. Lots of phone calls, skype and trips half in between or taking turns one flying to see the other.
I moved from Florida to Alaska in August so we could be closer.

My 4y/o son loves my BF and vice versa.

My issue is his kids. He has been divorced from the kids mom since the girl was 2 y/o and the boy 4 y/o.

Bf's son is 10y/o is diagnosed ADHD, BF refuses to give his son his meds when he comes for his visits every other weekend.
This makes the weekends miserable. Along with the issue that there is more than just ADHD wrong with his son. Nothing diagnosed but he has very odd behavior and behaves like he is Autistic. Having worked in Pediatrics in the medical field for over 20 yrs I have a very good idea when things aren't right. BF agrees that something is off about his sons behavior but says the ex refuses to take Son to Dr to get eval. I tell him to take his son to the Dr himself. He says he doesn't want his son on meds.

BF daughter is 8. She is in general very rude unless she wants something. She is very demanding, has no manners, tells her dad her mom tells her she doesn't have to listen to him. She thinks it's hysterical to fart loudly at the dinner table and announce "I farted" and laugh like she is 3 y/o. She expects presents every time she comes over and gets made if she doesn't get something.
Both refuse to eat the majority of the things we eat, none of their issues are allergy related, I refuse to cook them special meals, so my BF ends up making them their own meal.

Then there is the hygiene issue, both kids always come to the house reeking of BO, the 10 boy has to have his dad stand in the bath room while he showers to make sure he actually gets in the water and uses soap. We caught him turning on the water and dumping some on the body wash in the shower stream as he stood out of the reach of the water at the back of the shower. My BF has to smell his hair after each shower to make sure he has used shampoo. The boy will wear the same clothes this includes underwear everyday of his visit if his dad isn't paying attention.
The girl says, she doesn't have to wash her hair, that it's bad for it to wash it, she has hair almost to her waist. She is also bad about wearing dirty clothes all the time. My BF has to go in the bathroom and checking her hair after she gets out of the shower for the same reasons.
If we didn't insist that they take showers when they come over I'm not sure when these kids would get showers.
When we ask them when did you last wash your body and hair, they really have to sit and think about it, then the answer is usually 4 or 5 days ago. I demand that they shower before they climb into the nice clean linens on their beds.

This past weekend both his kids came into the house I share with their dad and I greeted them both and all I got was a yeah from the boy. The girl walked directly in my path and cut me off and never responded to my greeting.
She then went to her room without ever speaking to myself or my son who was so excited to see them both.
The boy stays in his room playing his handheld video game constantly unless forced to put it up, he is obsessed.
Besides the being rude there are other behavior issues, that I can't stand. I guess one of my biggest issues is I have noticed my 4 y/o is starting to copy their behavior because he sees them getting away with it. So it has gotten to the point that they are a negative influence on him.
I have taken to staying in my bedroom for the majority of the time they are at the house for the weekend, or I am taking my son to do things without them because I can't stand being around them. This past weekend my BF asked me if I was avoiding spending time with his kids, I told him yes.

When I talk to my BF about some disciple and setting some rules and boundaries he says that he only has a limited time with them and he won't ruin that time trying to fix what their mom has done to them. I have told my BF if he won't do something about their behavior I will have to find alternate living arrangements because I can not allow his kids to continue to affect my sons behavior in a negative way.

SO I guess my question is it best to move on or try and stick it out and try to help?
I have to admit that the thought of leaving him and his kids behind doesn't bother me one bit.

I am thinking it is best to remove these kids from my 4 y/o life.
Any opinions?