I would keep it simple and straight to the point
"Dear Alumni Coordinator,
The easiest way to reach me is through my father, at the address you already have on file. I would be grateful if you updated my name to Lil Bunny.
This way, the coordinator will have a current address to reach you and you don't have to give any explanations. If this person insists on getting the address you live in, then they are being very rude and you can repeat "Send any communication to my father's address" at will.