A Little Delimma

I know that when a issue in life arises that I can sit down and put it out on the table for all you good people. I value your advice and the combined years of knowledge that you offer me.
So, let me start at the beginning with this one...

A husband and wife neighbors and acquaintances of ours,  since we have known the couple,there has been mental abuse, and it has escalated into physical abuse. We, along with other neighbors  have all advised the wife to leave. But, like a lot of abused women with kids, she stays.
Recently, there was another incident and the wife wore dark glasses for a week. From what I understand the police were called. Not sure what happend after that, because they have been quiet.

Since that occurrence, She was  advised by several friends and neighbors that if she takes him back again, she will be on her own.  People are tired of the wife asking for help, only to ignore the help and constantly take him back.  Well, you can guess what happend. After he hit her like that. yup! She took him back,  I keep hoping and praying that nothing tragic happens in the home.

Then yesterday, our boys got an invite from their kids for a Christmas party.  They have two beautiful little girls that I just adore. Our dilemma in this matter is what to do? I do not condone spousal abuse at all, and do not wish to put my kids in an unstable environment where at any point the husband could snap.

On the other hand, I do not like to punish  kids for the actions of their parents. Kids do not understand any of this. And I know how as a kid I would feel if I sent out invites and no one showed up.  Thus the dilemma, just could use some advice from those out there who are wiser... 

-JUGM