13 year old hitting other kids

Hi, my brother's son has some behavioral issues.  He gets mad easily and can hit other kids, for example he hit my daughter quite a few times over the years.  When this happens, his parents talk to him and make him apologize and all that - but it keeps on happening again and again.  He is a good and responsible boy otherwise, but I think it has to do with his temper and it looks like he just blows up for no important reason and he cannot control it.  Every time this happens, of course I get upset and my brother and his wife first try do punish their son but then I notice they act as if they feel resentment towards me and my daughter - because she caused this because she was annoying or she wanted to do something he didn't want to do...So my problem is this, we have been a close family but it's getting harder now that I know that this boy will most likely hit my child again...Thanksgiving is coming and I feel like I should just tell my daughetr to stay away from her cousin (but that's goining to be hard because they are the only kids there).  I do not know if my brother and his wife are getting any counselling or anger management therapy for their son.  They get very upset when I tried to talk to them about what was happening...I guess the only way left for me in this situation would be not to go to Thanksgiving in their house - if I want to protect my daugher, she cries when he hits her but then she is very forgiving and the aunt gives her great gifts...It's like she gets a gift and she gets smacked, one plus one minus.  This boy is now 13 years old and he is a very big and strong boy.  Last time he hit her on the head with his fist - I think it is becoming too dangerous at this point.  Hitting does not happen every time they play/hang out together - but it happens, say, 60% of the time.  So it's like 50/50 chance.  Anybody has any idea if there is any way for our family to still meet for holidays - or should I just give up...

[margypops]

You have to take control that he is not around you all tell your family it is not allowed it is ,totally inappropiate for him to hit her, perhaps he needs a bigger punishment telling him off seems mild, so all I can say is dont have them round and dont go there tell them until he stops hitting her, you wont have him in the house .

[Sandman2]

   There is a very strong society norm that says boys don't hit girls.  After all these years, if he is still doing it, there exists the chance he can't control what he is doing.  My guess is that his school is starting to deal with this along with his parents.
  In your case, if thanksgiving can be done where your daughter is always with you and there is no opportunity for them to be alone. It could work out.  He is at an age where boys are either going crazy over girls or really don't care if they are around.  So he might be very happy (or sad) if they don't interact.  Another idea would be something like guitar hero that could be done and shared by a whole group of people.  Your daughter may also be mature enough now to figure out how not to trigger his violence.  But, I would still keep her close if you go.  Hope this helps.