This one time I was at a company get-together and the CTO, whose son was just born, received some Peppa Pig merch.
I exclaimed (in English) "Peppa Pig is the shit!"
The HR lady stared at me as if I killed her father with an accordion.
While I struggled to answer, he graphically gestured, and I agreed.
"But... also means... 'friend'?"
Oh. Big cultural difference. I had to explain how US males used insults as a proxy for affectionate gestures, to someone who uneasily spoke English.
He was not fully convinced, I think.
I can't resist linking this bit of linguistic humor: https://www.youtube.com/watch?v=igh9iO5BxBo