AITA for not telling my MIL what my SIL said?

AITA for Protecting My Teen SIL’s Secret From Her Mom?
AITA for not telling my mother-in-law what my teenage sister-in-law shared during a private heart-to-heart?
A trusted heart-to-heart with a struggling teen turned into a family standoff when her mom demanded to know everything.
The backstory and early dynamics
The narrator (30F) has been in her sister-in-law Riley’s life since birth. Now 14, Riley is hitting a rough patch—clashing with her parents, testing boundaries, and feeling overwhelmed. Unlike most adults, the narrator has become Riley’s safe space. Riley talks. The narrator listens. No lectures. No ultimatums.
The moment things shifted
During a casual “girl time” outing—sweets, conversation, and empathy—Riley opened up about her feelings. Nothing alarming. No danger. Just messy teenage emotions. The narrator chose not to report the details to her mother-in-law, believing it would break Riley’s trust for no good reason.
The final confrontation
The mother-in-law found out there was a private conversation—and was furious. She insisted she had a right to know everything happening in her daughter’s life and accused the narrator of “playing the secret game.” The narrator stood firm: she’s an adult, yes—but she’s also a safe listener, not a spy.
The fallout
Now the family is divided. The mother-in-law feels undermined. The narrator feels she protected a vulnerable teen. And Riley? She’s stuck in the middle, watching adults argue over whether her feelings are allowed to be private.
What Reddit Thinks
Verdict: Mostly NTA (Not the Ahole), with some mixed takes**
Top-style reactions:
- “NTA. Teens need at least one adult they can trust without fear of everything being reported.”
- “NTA. If there was danger, sure—tell the mom. But normal teen venting? That stays private.”
- “Soft YTA only if you keep secrets that affect her safety. Otherwise, you did the right thing.”
Reddit largely agrees: trust is fragile, and once broken, teens often stop opening up at all.
A Final Thought
When does protecting a child’s trust cross the line into keeping secrets—and who really gets to decide?