The Invitation

"Oh, I think you will, honey. Because if you don't then it's just possible that some of these pictures might just find their way onto your Facebook page!" Sally replied with a lovely smile. "And maybe onto fliers left all over the Department at college as well. That would be a shame, wouldn't it?"
"You wouldn't!" Jack exclaimed.
"I would, honey. I was really quite cross when you gave that picture to Mark, but fair exchange is no robbery, as they say, and if you are a good boy and do as you are told then I will forgive you. Now show Lucy your knickers!"

Jack heard the steel in her voice and knew that further argument with her was futile. He could walk out, but he was a mile from home and dressed as a not unattractive young woman and he didn't fancy the walk. And in any case, he realised, he didn't even have a door key! Alternatively, he could show Lucy his knickers and appease his girlfriend. Maybe then they could put all this aside and get on an enjoy the party. And if he did it now, before any of the other guests arrived...
And then it struck him. Sally had said that he was the party. There was no-one else – just him. The whole thing was a set-up. Sally and Lucy had contrived the whole thing just to get him to dress up so that he could be made to look an idiot, and so that pictures could be taken to blackmail him into never showing anyone the pictures of Sally again. He had been had.
“There isn’t anyone else coming, is there?” he asked.
“No sweetie. It’s just us,” Sally replied. “I’m sure that we’ll have fun though!”
“But your birthday...”
“Oh, it really is my birthday on Tuesday, but the party is next weekend. And Mark hasn’t really popped out – he’s having dinner with his parents. They did invite me as well, but as you can see I had other plans,” Lucy explained with a smile. "You see I had to help a friend with this little problem that she's having.