Tell him future transactions that he can pay you in any way he likes but if it's in fiat, he needs to cover the fees. This way if he wants to pay Paypal, he can pay the fees. If he wants to do a bank deposit, he can pay the fees.
However, you're willing to pay the fees if he'll pay by Bitcoin.
Problem solved and you won't sound like you're being difficult.
The thing is that i am who pays the fees on paypal transactions, and i lose too much money with it. I can offer him some kind of discount for my services to motivate him to pay me with bitcoins.
Yet the difficult part will be to convince him to register with ID/Passport.
