Screenwriter Justin Theroux reportedly convinced his fiancee Jennifer Aniston to help him write a comedy.

Initially, Aniston was reluctant because of her lack of experience, reports contactmusic.com.

"They worked out a story idea and a list of characters, and when Justin went away on a job for a week, Jen was so inspired she just kept on writing - alone," said a source.

The 42-year-old "Iron Man 2" writer was less than impressed with Aniston's efforts and it caused tension between the couple.

"Jen got the message loud and clear, shrieking, 'Are you kidding me? You're the one who pushed me to do this. I told you I wasn't a writer. Justin wisely zipped it as Jen angrily ripped up her pages and stormed off," added the source.