There was a movie broadcast on comedy central in the mid nineties involving a man and his brother/friend giving him flack because he was writing a book about a heartbreak of some sort. The reason his friend didn't approve is because the author guy was thwarting a newly developing relationship. Newfound romantic happiness wouldn't have supported his expertise on breakups/lonlieness written about in his book.

Sounds like Kissing a Fool (http://www.imdb.com/title/tt0120723/)