All the couples are back for a vacation in viva Las Vegas. Where the old saying goes, "What happens in Vegas...stays in Vegas." One of the lucky couples from the last film is getting married, so each of them split off into gender groups. Each gender determined to have the time of their lives before the big wedding. However, things go haywire, as this may turn out to be one vacation they may not soon forget.

Steve found out that his accountant died and when he did, he left 7 years of Steve’s tax returns that he never filed. Steve was paying but nobody was filing. In fact, tax payment checks that Steve wrote, were still attached to the returns but they just were not mailed out.