A charitable contribution

You're not attracted to the homeless man, but you have always considered yourself a giving person. You walk over to him and kneel beside his blanket. He stinks powerfully of sour booze and unwashed clothing. His bloodshot eyes fly open with surprise and the movement beneath the blanket stops.

"Ahm Shorry!" He exclaims drunkenly. "I wash jush shcratchin an itch!"

You give him your best smile and say, "Maybe I can help you scratch it...with my mouth."

You gingerly pull the blanket away from his lower body. He's wearing layers of smelly clothing but he has managed to **** down his pants and dirty underwear. His cock is very large and uncircumsized. It looks disgusting in his clenched fist.

"What are you doin'?" The old man asks with bewilderment.

It's a good question. Looking at the old bum's gross cock and smelling his overpowering aroma you're having some second thoughts.

Should you go through with it? Keep him at arm's, or at least hand's, distance? Or tell him sorry and move on?