Am I the jerk for giving my mother-in-law a fake copy of my house key and exposing her on Christmas dinner?

I want to preface this by saying that I, a 34-year-old female, married my husband, 37, a year ago.

His mum is snoopy and annoying as Frick.

She can't help it, that's just how she is, as my dear in-laws always say. My husband and I purchased a

new house recently. My mother-in-law kept pushing to get an emergency key. She promised that she'd only

use it in an emergency, but given the fact that she had an emergency key to our old apartment

and walked in on us being intimate twice, but my husband

didn't think it was a big deal, I just couldn't trust her. So I just sent her a fake key

after she kept pushing, and she had a smug look on her face after I hand delivered it to her.

Days gone by, and on Christmas dinner, my mother-in-law angrily called me out on the fact that I gave her a fake copy of the house key.

She shamed me for doing this in front of everyone else in the family.

But in my defensive state, I asked her how she found out.

And she said days ago when she came over at four while my husband and I were out.

I reminded her, didn't you promise that you wouldn't use it unless there's an emergency? So you try to get in

when there was no emergency and you broke the promise you made to us. She went red in the face,

and the other family started staring and some even laughed at her for the face she made.

She suddenly got up from her

seat and rushed into the kitchen, where she had a huge meltdown so loud the next door

neighbours must have heard. Literally, I've never heard a 60-plus year old woman throw a tantrum like

that. Needless to say, dinner went pretty awkwardly and my husband and his sister were giving me looks.

My husband went off on me on the car, and said I lied and manipulated and humiliated and exposed his

mum, and said he wouldn't have let me get away with it had he known.

...