I think all families have their qwerks... Fortunately, ours are not that serious.
Dh and I did meet through our parents, as a result, every holiday, celebration, etc (practically every weekend), we are all together. Recent "issues" which were resolved:
FIL at my mothers day party decided that my BIL was tasting dip with his fingers.... He was going to protest and not eat anything that I made. (I fixed that....)
MIL approached my mom on vacation and said her "Heart was heavy" about my mom not including cousin X at our wedding (22 years ago) (I fixed that too Mind you, cousin X passed away 5 yrs ago!)
Mom stopped my nephew from eating appetizers at above mothers day party. (He is struggling with his weight as a teen, but she stopped him in front of everyone, and drew attention to his weight : ( (Boy did I fix that)
Dad... Nothing recent....
So, I guess all in all, I would say that every family has complexities. We work through or let it pass, depending on severity. If it is serious, like you may be implying, I am sorry. Drama is not fun..