How many times has a marriage in the family ruined a family?

I heard of fathers not speaking to their daughters or sons because they married someone who's not from their community or religion. Although all those stories are stupid and childish, I heard one from my colleague which is heartbreaking.

Her uncle stopped talking to his daughter who married his brother's son. Yep not even cross cousin. I don't blame him.

That's one of the reasons a lot of people choose to never get married.

My step mom and step dad, sucked shit.