My girlfriend is out in the car
A man had been drinking at the bar for hours when he mentioned something about his girlfriend being out in the car. The bartender, concerned because it was so cold, went to check on her. When he looked inside the car, he saw the man's friend, Dave, and his girlfriend kissing one another. The bartender shook his head and walked back inside.
He told the drunk that he thought it might be a good idea to check on his girlfriend. The fellow staggered outside to the car, saw his buddy and his girlfriend kissing, then walked back into the bar laughing.
"What's so funny?" the bartender asked.
"That stupid Dave!" the fellow chortled, "He's so drunk, he thinks he's me!"