Back in the 90's I worked at a large outdoor retail sports company for part time work (mostly nights or weekends), but more importantly, picked up some great employee discounts on merchandise.
One girl I worked with never seemed happy, just kind of like a fuddy duddy who didn't like her job. One night she seemed all happy and excited, and I joked with her that she must have had or is going to have a hot date.
She reported me for ****** harrasment, the manager had to write me up. Pretty much one of the few times I've ever been reprimanded in my life working, and it was on a part time job I didn't need.
Looking back, yes, I was wrong about the comment I made and I did learn my lesson. I worked with her for over a year before that and never a problem until I made that comment only in jest and I honestly didn't mean anything by it.
It was a learning lesson on my end.