And in german (if I’m not mistaken) fox is Der Fuchs, so boy.

That's true, but the grammatical gender has nothing to do with the actual gender. Nobody thinks that all foxes are male, just as nobody thinks that spoons (Der Löffel) are male or the street (Die Straße) are female. They can also change depending on the amount. For example, if we take "Haus", which means house, we say "Das Haus" if we talk about a single house, which would be neutral, but refer to multiple houses as "Die Häuser", which would be female. Nobody thinks houses become female once there's more than one tho.