When Kelly gets invited to her ex-boyfriend's wedding in Mexico, she doesn't want to show up alone – so she decides to bring Cooper as her plus one. But when getting to the wedding becomes a south-of-the-border logistical nightmare, Cooper enlists Neal, Barry, Josh and Leslie to come to their rescue.

When Barry and his new girlfriend, Ashley, seem to be moving too fast, Cooper, Neal and Kelly try to intervene before he gets in too deep. Meanwhile, Josh's attempt to outshine his co-worker leads him into dangerous territory.