So we have a brand new staff member in my team who has a perfectly sensible name - Steven but has decided to use some ridiculously stupid nickname he made up - Sonty 
And he is now constantly correcting all of us and insisting we use his nickname. I am his manager. I feel silly even uttering Sonty. Yet he corrects me every time I say Steven.
Aibi to want to take Sonty and shove it up his bum!
PS not his real name or moronic nickname but they are similar to what I said.