A Toronto woman, who goes by the name @JodiesJumpsuit on Twitter, has revealed an innovative trick that she used to stop her teacher from pressing his crotch against the desks of female students.

In a series of tweets, the woman disclosed how a piece of chalk came in handy to expose her teacher's inappropriate behaviour when she was in high school.

"So when I was in high school long ago there was this one male teacher who would walk around the class and rest his junk, through his pants, on the edge of your desk, if you were a girl," the woman tweeted.

The teacher "didn't particularly like our class, the one just before lunch, and we didn't particularly like him. The junk resting only aggravated it", she said.

While their teacher's behaviour troubled them, the students were not sure how to approach other teachers for a remedy.

Jodie continues: "How to deal with it was a bit of trouble, because what teenager wants to acknowledge their teacher's b***s on their desk? Or on someone else's? To that teacher? Or another teacher?"

Besides, "plenty of the boys didn't believe it", so she decided to do something to prove it. She rubbed chalk in front of the desks of female students, so that it would leave its mark on his pants.

"Halfway through the period, the class not only believed the claims of the students, the evidence was as plain as a line of white chalk rubbed against the crotch of khaki pants," she said in her social media post.

The woman added that the teacher spent lunchtime attempting to clean the mark off his pants and that he seemed to learn his lesson.

"And the kids for next semester knew exactly what to do if he started it up again. I don't think he did. The end. Happy Halloween!" she ended her tweets on the subject.

A lot of people on Twitter applauded her for her amazing trick. One follower said: "girl. This thread just made my night, pure genius; a lot of us have had similar situations. Unfortunately #MeToo (sic). Another user said, "Very well played... and you are a real hero!"