Good evening
It didn't offend me, it just made me laugh to see such a nickname.
I've always remembered to translate my nicknames if I ever use words that don't come from the languages I speak.
For example, my current nickname "Louca" means "idiot" in my mother tongue, and some people who speak the same language as me or who speak Portuguese have come to tell me that my nickname means "idiot".
And yes, French is quite a complicated language, especially when it comes to spelling, with hundreds of conjugations and exceptions and other things.
So it's better to learn it from an early age, because at that age you learn faster.
French is not my mother tongue but I've been living in France for 9 years now (I'm 14) so I learned French as a child and it was easy.