"Will Work for Fellatio"

So I'm eating lunch in Washington Square Park and reading my new book*, when an older black man asked me if I could spare some change. I could, so I gave him some. Next he asked if I could spare a cigarette, but I told him that I didn't smoke. Then, he asked me if I could spare a blow job.

'Excuse me?'

'A blow job. Can you spare a blow job for an old man.'

'Sorry.' I was seated on a low bench in front of him and he was standing above me.

'Ah man, everyone's got a blow job to spare!' he complained. 'Are you telling me you need me to give you a blow job because you don't have one yourself?'

Be careful. That's bound to be a trick question.