I love my husband but not his kids

We have been together on and off for 3 1/2 years. It really bothers me how he is with his kids, they are spoiled rotten and only come to him when they want something like toys or money. He let's everyone walk all over him but fights me tooth and nail when I need help financially. They are disrespectful and don't clean up after themselve, his youngest is 13 and severely overweight, he sits around watching disturbing inappropriate videos on YouTube all day and stuffs his face full of junk food, my husband almost encourages this by replacing all the junk food I throw away. When I tell the boy he needs to ask before snacking he cries to his dad and makes me the bad guy, then my husband and I fight about it until I end up apologizing. He doesn't shower or brush his teeth either, it is a constant battle to get him to do anything and he always complains about how his teeth hurt or his throat is sore and when I ask him how long it's been since he brushed his teeth it's always over a week. He is sick all the time and cries about everything to get his way. He only visits on the weekend but when he is here I lock myself in the bedroom because I can't stand to be around him, he stinks up the whole house because he constantly farts and burps, it is disgusting. The 16 year old has been stealing money and smokes Marijuana in the house, he has grown up a lot and has been more respectful but I have a bad feeling about him. I think he is doing other drugs as well. When I try to talk to my husband about how I feel and I don't agree with these things he says it is out of his control and he doesn't want to push them away so he let's them do it, am I over reacting?