Even better, she should have left.
My brother was married to a psycho and one night after an argument he was sleeping and SPLASH, the wife dumped a pan of cold water over his lower parts. . .she said next time it would be boiling water.
Not funny and he left right away.
Also, imagine the story slant if it was the guy that sliced her breast. . .oh boy, there would be no jokes whatsoever, but there would be calls for his murder and no people would be saying he should have fed the breast to some dogs.
Well there is this, from 2017.
https://www.dailymail.co.uk/news/article-4805638/Man-cut-girlfriend-s-nipples-pleads-guilty.html