I just finished watching a on YouTube.

The host discusses the negative impact of triangulation between siblings:

• Pits siblings against each other
• Creates a division, hatred, tension, anger, resentment, and competition
• Roles that we take on when we are forced into triangulation between siblings

When one sibling triangulates me and I call them on it (smear campaign against me), it just escalates their hatred of me which is exhausting to absorb BUT it is validation for me that I'm doing the right thing, by sticking up for myself.