Eddie Cantrow (Stiller) is a terminally single San Franciscan, sick of being hounded to make the most of bachelorhood by his lecherous dad Doc (Ben’s real-life father Jerry Stiller) and henpecked best friend Mac (Rob Corddry).

After spending Valentine's Day at his ex-fiancée's wedding, Eddie runs into beautiful blonde Lila (Swedish actress/rock singer Malin Ackerman), an environmental researcher with a picture of David Bowie on her knickers.

He quickly falls for the gorgeous stranger and, when her work threatens to move her to Rotterdam, impulsively marries her.

However, on their road trip down to a Mexican honeymoon resort, Eddie gets to know the real Lila - crude, annoying and with a penchant for very rough sex.

Things get worse for the jittery groom once they reach their tropical paradise as Lila's former coke addiction and chronic debt problem are revealed. When a blistering case of sunburn confines her to their room, Eddie welcomes the chance for some alone time at the bar... where he meets Miranda (Mission: Impossible III’s Michelle Monaghan).

She's a sporty brunette vacationing with her family and soon Eddie is spinning elaborate tales to leave Lila behind and spend time with his new gal-pal, who has no idea he's a newlywed.

To be fair, Eddie makes a couple of half-hearted attempts to come clean, but is still more than happy to get swept along with events when he keeps getting interrupted.

The truth is inevitably revealed and the hapless husband is dumped. Twice. Can he convince down-to-earth Miranda that she's the one he really wants?