All the couples are back for a wedding in Las Vegas, but plans for a romantic weekend go awry when their various misadventures get them into some compromising situations that threaten to derail the big event.

Marcus finds himself in love and married to not one woman, but two.

Henry is a player skilled at seducing women. But when this veterinarian meets Lucy, a girl with a quirky problem when it comes to total recall, he realizes it's possible to fall in love all over again…and again, and again. That's because the delightful Lucy has no short-term memory, so Henry must woo her day after day until he finally sweeps her off her feet.

On the eve of her 19th birthday, Nina finds out that she has been cursed since ancient Roman times by Emperor Justinian. She carries a plague that can wipe out the human race. The Book of Fire reveals that Nina can choose to live and infect millions, or avoid the fate by spending eternity in purgatory. She has three days to decide, and so Nina has no choice but to make her own destiny.

Bernie and Joan are two fiery flirters who are passionate about everything from hookups to breakups and each other. When he sets up his best friend, Danny, with her roommate, Debbie, the sparks soon fly as they try to navigate the relationship minefields from the bar to the bedroom and are eventually put to the test in the real world.