I once knew a very beautiful woman who was going with a friend of mine. Another friend of mine had to go away for a few weeks and he entrusted me with his Martin D-35 for safekeeping.
We all lived in the same apartment complex, so one day I take the D-35 over to the the friend with the hot girlfriend to show them and play a few songs. The girlfriend tells me that her ex once got so mad at her the he smashed his own D-35 in anger.
My wife knows the value of my gear and she's very careful around it. If she did that to one of my guitars...first off she'd feel terrible, second she'd offer to buy me another one.
I understand real accidents happen, so I honestly wouldn't be harsh with her at all.
However...as soon as she wasn't around...I'd cry, roll around on the floor, stomp my feets, and then see just how far I could kick the outdoor garbage can. The thing is, she'd never know about it.