My boyfriends Dad has physically abused him all his life, worse when he was a child but not brutally; though he will still be threatening and sometimes strike him .
He doesn't support the family at all , he has no job or anything . Though I assume both his parent's name is on the mortgage, his mom is the one who works.

He has threatened to kick my boyfriend out of the house, who in all honesty has caused no trouble. He doesn't do drugs, he's a straight A student and is planning on being a doctor. He has never been a problem other then the typical semi mouthing teenager that we all are. He is only sixteen years old , and his mother doesn't want him to go as well as his father is doing illegal business stuff over in the states - not completely sure what he is doing but it's not legit.

Can his mother kick the father out of the house? & can my boyfriend himself be kick out?

It depends on where you are - the father can be arrested for "kicking" the boy out in most States. However, the father can claim the boy is disruptive, "in need of supervision" (the key phrase in NY) and ask permission to have him either made a ward of the State or force him out of the house otherwise. Of course the mother can file for divorce and ask that she remain in the house. There is no way of knowing if she would succeed. If the mother doesn't want the boy to leave but is powerless to stop the father from kicking him out I would assume she is not going to file for divorce for whatever personal reason.

You say the father has no job and doesn't support the family (which is rather immaterial) but that he is doing illegal business stuff, presumably for money - what is that about?

How bad is the mouthing off? Bad enough that the father has had enough?

We live in Ontario .
I'm not completely sure what it is . He told the family he started a mechanic shop over in the states and would disappear for days, I don't think what he is doing over there is reallly what he is doing & is most likely have an affair of sorts. But he been flagged so he cannot cross the boarder anymore into Detroit.

He sits at home and plays video games all day,
I mean the father usually starts the fights; this man doesn't do anything, doesn't clean up after himself, doesn't have a job, and makes the wife do everything clean cook work & walk to wherever she needs to be.
Resentment is obviously strong in this household, the mouthing off isn't very bad, the usual shut up, slams doors etc. But the father usually takes it farther & hits him , kicks him, scratches his face at times - how else do you have to defend yourself.

I believe the mother is to scared to leave her husband, from my understanding she wants to but is frightened .
Thank you for your help .

No one "makes" anybody cook/clean/work/walk wherever - she does have the ability to leave. She may not have the courage, but for whatever reason she is staying in this relationship. I'm startled that she is staying and watching her son being abused.

I don't know that saying "shut up" to your father is usual behavior - not in my house!

If the father cannot cross the border there is a reason - and it's not that he's having an affair.

The mother is the only person who can stop this and protect her son. I don't know if she has the courage to do that.

The father can't just summarily kick the boy out. He should be speaking to someone like a school counselor or clergy person to help him figure out what to do.

I presume that you don't spend a lot of time in his home. Most likely, if what you have described is true, both the mother and the son would live isolated, controlled lives at the hand of the father, who sounds like a total brute.

I also assume that you are only 16 years old as well. The problems this family has are far beyond your ability to help. You have no first hand information as to what the father is up to, only what your boyfriend has told you. I'm not saying he is being untruthful, but he could be painting a picture that is not entirely accurrate.

I don't think it is your business to know what his parents do as far as who's employed, or who isn't allowed to cross the border or whether the mortgage is in both their names. If this is also information you are getting from your boyfriend, and his parents don't share the detail directly with him as to their personal banking, employment etc. at best you are getting only a part of the truth.

Not enough to make assumptions on, and not enough to judge them.

If you have actually seen bruises, scratches etc. from these attacks the father inflicts on your boyfriend, this didn't start overnight. What has he done to get help- has he called the CAS, or talked to a school counsellor along the way, or has anyone else noticed and called on his behalf?

Considering the circumstances, you could speak with a school counsellor as well, and alert them to the apparent abuse going on, if they aren't aware already. Other than contacting the authorities, with knowledge you actually have, (pictures, dates, times, police records etc.) to see if there can't at least be some sort of investigation on the abuse issues, there is nothing you can do on your boyfriends behalf.

There are provisions for 16 and 17 year olds with the CAS.

Reporting Child Abuse & Neglect It's Your Duty Your responsibilities under the Child and Family Services Act (http://www.children.gov.on.ca/htdocs/English/topics/childrensaid/reportingabuse/abuseandneglect/abuseandneglect.aspx)