I am going to try my best to make this a short as possible.
but it is still really long, so sorry about that.

Okay, well to start I don't have a big house.
me and my husband have a very small 3 bedroom house.
and not even big bedrooms.
And as of right now it is over packed.
My ex-sister-in-law, my 3 nieces, my parents, my 5 kids, and my oldest son's girlfriend are all living in the house.
And I don't even have a room anymore, it's getting so bad.
All of my son's don't have a room. '3'
and my daughters have to share with their cousins.
and then my son's gf is staying with us because her parents decided to go on a second honeymoon. and since she is 5 months pregnant with my grandchild I felt like I had to let her stay.
and then my mom is extremely sick, and my brother is an @ss and so I am letting her and my dad 'who is to old to take care of her' stay with us also.
But my husband told me yesterday, that he can't take it anymore.
and that he wants his house back.
I feel bad telling any of them to leave.
My list of who to kick out is not really easy.

It's between, my ex-sister-in-law who my brother had an affair on, and their 3 kids. 'who he doesn't even see anymore, because his gf is expecting and he doesn't want anything to do with his ex'
She doesn't make a lot of money and can't afford to buy even the smallest apartment, and my brother isn't paying her anything yet.
Or my parents, who are extremely old and I would feel horrible sending them to a nursing home. My entire life my mom has always told me that she took care of me and my brother so she wanted us to that for her and our father when they needed it and she hates nursing homes.
So since my brother is a @ss, I'm stuck with them all the time.
and then my son's gf. she's only 16 and pregnant, so I would feel bad telling her to stay at her house alone til her parents get back.
which is in I think they said 4 weeks.
I think it was dumb to leave their pregnant daughter for that long, but from what I was told it's like a mid-life type thing.
and with her having a baby, they think they are getting old so they want to enjoy life or something like that... i don't know, it sounds like a bunch of crap if you ask me, but anyway.

So it's a tough situation I'm in.

I don't even know what to do, or who to tell to leave or anything.
I would love to get my room back, but I hate...
well I hate all of this, it's just really confusing.

Basically, if you were me what would you do?

and my kids are all young, 4, 8, 12, 14, 17.
so I can't tell them to leave either, and I probably wouldn't anyway.

You must without a doubt should get the humanitarian world award! Keep parents and sons. That your immediate family The rest GOES! What you are doing is becoming an enabler to everybody. Take good care of parents. The rest of the immediate family got to go. The rest left need to work and help out mom or the older ones needs to pay room and board.I would just tell the rest that they need to go and your brother too. It will be tough but its too much drama for grandparents and your husband and kids. Don't be an enabler, like booze to a drunk. If they just tell them you can solve the problem and will sell the house and your hus'grand/sons will go live somewhere else Be assertive and you have your husband to back you up. This is a man telling you this. Tell them this is what you want for Christmas.

I agree if you don't make them get out they never will.
Has the ex sister in law applied for child support or any assistance?

You must without a doubt should get the humanitarian world award! Keep parents and sons. That your immediate family The rest GOES! What you are doing is becoming an enabler to everybody. Take good care of parents. The rest of the immediate family got to go. The rest left need to work and help out mom or the older ones needs to pay room and board.I would just tell the rest that they need to go and your brother too. It will be tough but its to much drama for grandparents and your husband and kids. Don't be an enabler, like booze to a drunk. If they just tell them you can solve the problem and will sell the house and your hus'grand/sons will go live somewhere else Be assertive and you have your husband to back you up. This is a man telling you this. tell them this is what you want for Christmas.

See I would kick the lazy son out too. If he was man enough to get a girl pregnant, then he should to be man enough to support family he has created. All of the exes should get out along with the cousins. You are not a boarding house. Give them 30 days to get out!

You must sit everyone down and explain that, although its nothing personal and you love them all the house is NOT big enough, and so some have to leave.
I think you have every right to kick out exacly who you want but in my opinon I would ask everyone other than your immediate family i.e. your sons and parents.
Maybe if your son that has got the 16 year old girl pregnant should consider getting them their own place too.. I am not sure if it is at all possible but 450donn (above) is right, if he is man enough to get a girl pregnant he should be man enough to support her too.
I know this is quite blunt but you must be firm, you should not have to carry on like this!

:)