The Wrong Cheeks

I live in Montreal, but my French is very basic. 

A while ago, I was chatting to a coworker about shaving. I’d recently learnt the word for shave in my language lessons, so I wanted to impress her by saying I shave my face in French. I’d forgotten the French word for face, though, so I just used the English word:

Me: “Je me raser mon face.”

She gave me a bemused look and asked what I just said.

I repeated.

Me: “Je me raser mon face!”

I then made the action of shaving my face.

It turns out that in French, there is a word fesses (pronounced similarly to the English face) which means buttocks. 

I told my coworker I shave my a**.