Screenwriter and star Jason Segel told New York Times interviewer Dave Itzkoff that both the naked breakup and Dracula puppet musical scenes were drawn from his real life experiences. In the article, Segel admitted that he really did once have a girlfriend who broke up with him while he was completely naked (although rather than being devastated during it, he thought to himself, "This is hilarious. I cannot wait for her to leave so I can write this down.") And before he was a successful actor, Segel tried to write a musical adaptation of "Dracula" for puppets.
The numerous bottles of wines that Peter, Rachel, and Sarah go through at the dinner scene are all red wines from Clos du Val in Napa Valley, California.
Kristen Bell damaged her knee whilst filming one of the horse scenes for the movie, which didn't end up making it into the final cut, however she can still be seen walking with a light limp in scenes towards the end of the movie.