Ignore it, or...
Spread the rumour he's a "Secret Millionaire" like the TV show and he's going to be giving out large amounts to deserving people.
Yes yes yes, I know that is the correct answer/solution, and I've told him that too, but G Jnr is G Jnr, a youngster that hasn't yet fully learnt how to deal with a werld full of arse wipes, and has consequently taken great offence.
It's the way he is at the moment unfortunately, but he'll learn gradually.