I did that once.  I had a boss who continually groped me, despite my insistence that he stop.   One day the business had a big function, and in front of two people my employer turned to me and said, "What do you think?"  He had an awful look on his face, like he enjoyed making me uncomfortable.   

I reached out and got a good feel of his stuff as I said something innocuous in response to his question.  You should have seen the guy.  He turned so red.  The next day he apologized to me for his past behavior.   He said he finally understood why I didn't want to be groped.  I hope he meant it.  I know one thing, he exercised more caution with women after that.