Isn't Fendt a nickname for a little boy?
I am quite sure it isn't. You might be referring to the Dutch "vent", which indeed would be meaning "young man". That would not work though, the best bet would be to use "ventje" (Little boy).
As written: He used "Fendt" as a nickname to spare himself and his family the blame. Fendt is widely known in Germany though: As a manufacturer of agricultural machines ... as in "John Deere".
So maybe he did think about his nickname and the size of his todger? (Well, that's how men are, innit: They always seem bigger than they really are...)