She is my sis-in-law, I am married to her brother. She however is not married but her and her boyfriend have been together 4 years. But that still dosen't give her a right to do what she has been doing. He stays with her and her older sister who already has two kids in a little house.

Oh, okay. Well I would have to wonder about that whole arrangement, too- him living with 2 sisters and everything. That doesn't sound healthy at all. And I don't think those children are in a safe environment.

No they are not in a safe enviroment, I could list a million things why they aren't. I won't list them all but here is a few that I have noticed,
1). The older sisters son is 3 years old, and does not even know how to talk yet! No one teaches him anything.
2). They curse at these kids. She also has a little girl who is 2 years old and they call her a hoe all the time!
3). They don't disapline those kids, so they have not learned how to obey their mom or how to act in public.
4). The older sister (the mom of these two kids) Is always bringing in different guys to the house to sleep with her, and the kids think that all of the guys are their daddies. I know how sad is that?
5). Both of the kids real daddies have gone back to Mexico. So neither one of them have any fathers.
6). They all smoke in the house, so the kids are always around cigarette smoke.
7). They do not get feed right. Shes always getting them kids meals which are not healthy.
So these are just a few things that are wrong, but they are about to bring another baby in this houdsehold! I know it will probably be premie, because she is not doing healthy things that a pregnant woman should do, she smokes, eats unhealthy foods, takes medicines that she isn't suppose to,etc. Don't this sound awful?

Oh yes it does sound awful! Can you or someone report them? Those kids could possibly be taken out of that environment if DHS or someone like that could get involved! No child deserves to be living like that!

I know I wish someone would do something about it but his family would probably disown me if I did it!

Sorry, I don't care if they did disown you and never talk to you again. You report these people and that is the end of it! Chrildren die everyday in these kinds of houses because no one speaks up for them. Be there for them, please!