Wrong Number: College Edition

It was last Wednesday night, and Mark was sitting in his dorm room watching
television when the phone rang. "Hello?" he said.
A girl's voice came over the line. "Can I speak to Ben, please?"
Mark who lives by himself, and whose name definitely is not Ben thought it was probably
a wrong number but was bored decided to play along. "I'm sorry, he's not in right
now. Can I take a message?"
"Do you know what time he'll be back?" she responded.
Mark replied "I think he said he'd be home around 10:00."
Silence on the other end... a confused silence. "Is this Steve?"
Having enjoying himself so far Mark responded, "Yes, it is. Do you want to leave a message for Ben?"
"Well... he said he would be home tonight and asked me to call him,"
she said in a slightly irritated voice.
He replied, "Well, he went out with Karen about an hour ago, and said
that he would be back at 10:00."
A shocked voice now: "Who's Karen?!"
"The girl he went out with."
"I know that! I mean... who is she?"
"I don't know her last name. Look, do you want me to leave a message
for Ben?"
"Yes... please do. Tell him to call me when he gets home."
She was sounding pretty irate at this point, and he could hear her temper
flaring. "I sure will. Is this Jennifer?"
She exploded, "Who's Jennifer?"
Apparently she wasn't. "Well... he's going out with Jennifer at 10:00. I
thought you were her. Sorry... it was an honest mistake."
"Ben's the one that's made the mistake! Tell him that Alice called him and
she's very upset and that I would like him to call me as soon as he gets home."
Mark smiled and said, "Okay, I will... but Becky isn't going to like this..."