So this is a little different.
Lizzie and William have been friends forever. She has no family, he didn't really like his parents. Now William is calling in a favor that she owes him, and he intends to collect.

"What do you mean I have to be married before the end of the month?" William stood and looked at his father's multiple lawyers standing in front of his desk.

"Your father was quite clear, sir. You must be married to take over his company." The main one just stood there as he doled out the same thing he had been saying for the past hour.

"Who does the company go to if I don't get married?" William was afraid of the answer.

"It goes to your cousin Anne, who has already agreed to run the company.'

"Well tell her to forget it. My girlfriend and I will be married before the end of the month and he won't get the company!"

"I'm sorry sir, but from what I gather, you don't have a girlfriend."

"I do though. I just keep her away from work thats all."

"Very well sir, but I expect an invitation to the wedding." And Mr. Fancy-Pants Lawyer and his posse turned and left William's office.

"Well shit. Who am I gonna find who will want to marry me for one year and then leave me and my company in peace."

"Mr. Darcy, Miss Bennet is on line one for you." The intercom rang in his ear.

"Lizzie is on line one..." Thats when the idea popped into his head. He picked up the phone. "Hey Liz. What's up?" All he heard was sobbing. "Aw Liz, I told you that Clark guy was bad news. Listen, I know this is awful of me, but I'm finally calling in that favor I won off of you. Meet me for lunch, one hour, normal spot." The sobbing turned to a whimper and a small recognition of an OK came over the line. One hour later, Lizzie was sobbing in his shoulder when he finally pulled his deal out. When he had finished telling her about her problem, she just stared at him.

"You want me to do what?" She stared at him like a deer in the headlights.

"I just want you to marry me for one year, then I'll give you whatever you want and we go back to being best friends. Lizzie, I can't trust anyone else. You got me through college, breakups, my parents' death. Please, I just need this one massive favor." William wasn't used to pleading for anything, let alone help. He just prayed it worked.

"Fine. No family, and all I do is teach at the community art center. It doesn't have to be a big thing does it?"

"Nope. Just invite some people that didn't know you've been in a relationship and call at the last minute."

"Not a problem, no friends, remember?"

Three weeks later, they were married in his backyard. Only the lawyers of William's showed up and a few distant relations that had known about their friendship and just assumed it had grown into a marriage. One by one guests left the reception at William's house. He then showed Lizzie to her room and they went to bed. William fell asleep that night, glad that he had kept his father's architecture firm. He had big plans to become a company whose buildings were self sustaining. This could work. He thought as his eyes closed. We're too good of friends to do anything serious together