NC for this as outing and will keep some details deliberately vague. So it has irked me in the past that on the occasion (not often) that we do have to pull up DD7 on her behaviour that my MIL sits there sniggering and stiffling giggles. It feels very undermining. It hasn't happened a lot as a) we don't have to pull up DD on things that often and b) we don't have MIL with us all the time. There is some background with MIL...she had a very volatile relationship with FIL (they are now divorced) and as a result DH was caught in the middle and I think it was all very toxic. She can be manipulative and has lied to us in the past....as a result we have quite firm boundaries. But regardless of this, our relationship (I thought) was OK and DD adores spending time with her which is lovely. We have very different views of parenting and are very different people but rub along OK.
Last time this happened I took her aside and asked her to please try not to react as we were trying not to encourage certain behaviours...this caused histrionics from her and apparently I'm ridiculous and she feels she has to walk on egg shells. My husband wasn't there unfortunately....but she told me he would think I was ridiculous too (he doesn't btw!). Has anyone else had to contend with this?