(Completely dated now due to sexual harassment; dates back to the 1970s):
Boss wants to have sex with his secretary, but she has a boyfriend. Finally he asks her flat out, "Let's have sex - I'll pay you $100."
She refuses. He replies, "I'll throw it on the floor - you bend over - as soon as you stand up, it's over."
She calls her boyfriend, who says, "Tell him to make it $200 and bend over as soon as he throws the cash down. He won't even get inside."
They agree to seal the deal that afternoon. The boyfriend waits for the call - and it comes 45 minutes later. "What took so long," he asks.
The secretary replies, "The bastard used pennies!"