A young guy drops off his girlfriend at her home after being out together on a date. When they reach the front door he leans up against the house with one hand and says to her, "How about a blowjob?"
"What! Are you crazy!"
"Don't worry, it will be quick, " he ensures his girlfriend.
"No! Someone might see us..."
"It's just a small blowjob, " he insists, "and I know you like it."
"No! I said no!"
"Baby... don't be like that."
"Come on baby pleeeeaassseee"
"I'm not going to give you a blowjob"
"Why Not...baby it will be quick I promise?"
Suddenly, the girl's younger sister shows up at the door in her nightgown, with her hair a mess, and rubbing her eyes. She looks at them and smirks, "Dad says either you blow him, I blow him, or he'll come downstairs and blow the guy himself... but for God's sake tell your boyfriend to take his hand off the intercom."
[Shamelessly stolen from A Trainwreck In Maxwell]