The Chemistry between Sam Rockwell and Olivia Wilde' damaged characters is the affair that both their failing marriages needed....so much so that it actually renders this film endearing.
I really loved it from the opening titles and the playful score to the ending. I'm not married myself but from what I've seen from the outside this movie, I think, would resonate with most - that's why it's a cliche.
I found it very charming and fun. I've had no problem seeing it again and again.