Messy boyfriend

I've been with my boyfriend for almost two years. We don't live together. He has 2 son's full time and I have 1 daughter full time so it is hetic.
Ive only just been realizing over the past few months though how dirty and messy he is! His the type of guy who won't shower for a day or two in a row even 3! He never washes his bed sheets unless I do it. His oldest son's room's window was cracked before I meet him and he still hasn't got round to fixing it just put a board up over it. I decided to change his kids sheets the other week and omg where they discussing. So his room has been locked up in the dark for almost 2 years so it's covered with dust and just so depressing in there. He doesn't teach his kids to lift the toilet seat so there is always wee on the seat and they always miss but he never cleans it up. I went to his on the weekend I hadn't been round for a while and the dishes were to the roof mouldy food on the bench the house smelt bad from the toilet room. His shower had slim on it. His a smoker to so his always coming to bed smelly and wants to have sex! Ha no way buddy haha. But on top of all that. He doesn't bother bathing his kids most nights and they always smell and look mucky. Not to mention all their teeth are never brushed and their breath stinks. I don't know how they arnt sick.
I've always been the clean girl. So it's driving me insane. I've got a love for linnen too. I've always been the Egyptian cotton girl who sells her arm and leg for sheets and dooner covers and he will just put his sons to sleep in the bed and him self so I'm forever washing the sheets. As they stink and have marks on them. When he drinks his red wine his clumsy and spills it on the couch and the carpet. My bench is stained, and will he bother to clean it up. Nope!
This morning one of his kids got into my daughters left over birthday cake and put it every where all over the house. But my partner didn't see this as a problem. It wouldnt really be if he helped clean it up off the walls and floors. And their all very rough too. They have put a hole in on my my doors and his oldest a while ago through a toy truck at the wall marking it. My boyfriend did go off at him and took the truck to he cleaned the wall but an hour later he just gave the truck back. There is blue food die all over the carpet in one room. Why does he see this all to be okay. I wouldn't really be this up set it's just I'm renting. I won't be getting my bond back at this rate.
I changed his oldest one day and told him he had to out on clean underwear he did but then went to put the dirty pair in the draw. I told him they had to be washed but he told me they don't have marks on them so they are clean. Turns out his always been doing this.
I walked into my bathroom last night when my partner was finally in the shower and there was this smell it was coming from his clothes. I've never smelt anything like it!! It was a terrible terrible smell. I felt sick. His only just getting worse
What does every one suggest I don't know how to come to terms to tell him he is dirty and I don't think I can ever live with him to he changes but to me that sounds horrible. He isn't a scummy type of guy very polite has a very good job, earns alot of money owns his own house. I'm beginning to not be so attracted to him any more and I don't want that. When he scubs up nicley my stomach flips his a very good looking guy. But I guess only when he is going some where nice and decides to shower and put on clean underwear. So I don't get why he is like this when the rest of his family arnt.. am I being awful? I just don't know how to be around him sometimes and how to tell him why I don't want to have sex with him. His dick smells so bad too 😔