The IRS decided to audit Grandpa and summons him to the office. The auditor was not surprised when he showed up with his lawyer. The auditor says, "well you have an extravagant lifestyle and no full-time employment which you explain by saying that you win money by gambling. I'm not sure that the IRS finds that believable.
"I'm a great gambler and I can prove it" says Grandpa. "How about a demonstration?". The auditor thinks a while then says , "Ok Go ahead". Grandpa says, "I'll bet you $1k that I can bite my own eye". Auditor thinks a minute and says, "Ok it's a bet".
Grandpa removes his glass eye and bites it. Auditor's jaw drops and Grandpa says, "now I'll bet you $2k that I can bite my other eye". Auditor can tell Grandpa isn't blind so he takes the bet. Grandpa removes his dentures and bites his good eye. The stunned auditor now realizes he has wagered and lost $3k with Grandpa's lawyer as a witness.
Auditor is getting nervous. Gramps asks if he wants to go double or nothing. "I'll bet you $6k that I can stand on one side of your desk and pee into your trash can on the other side without getting a drop on your desk". Twice-burned auditor is cautious now but he looks carefully and decides that there is no way he can possibly accomplish that stunt so he agrees to the bet.
Gramps un-zips. He strained mightily but could not make the stream make it to the other side. The auditor leaps with joy realizing he'd just turned a major loss into a huge win. (he won $3k)
That is when Gramps lawyer lets out a moan and sets there with head in hands.
"Are you OK?", the auditor asks.
"Not really", says the lawyer.
Lawyer mutters, "This morning Grandpa bet me $25k that he could come in here, piss all over your desk, and that you'd be happy about it".