Lie Cheat Steal. Harry Delaney Adventures, #1.5

It's a vacation. What could go wrong? Sasha Delaney and Barbara Williams are feeling housebound. Responsibilities of husbands, children, and business are taking a toll. A quick getaway would go a long way to improving their outlook on home life. Plans go awry when a sudden change in destination finds them south of the border down Mexico way. It's not their first trip across la lìgne. It might be their last when they run into an old acquaintance who gives them a choice. They can go along, or they can work off a debt in a house of ill repute where the rates are low and the outlook for a future is dicey. Husbands Harry and Mike become disenchanted with the whole vacay thing when the wives don't, or won't, check in.
That in itself isn't unusual. They're forced to grin and bear it until a phone call is finally answered and they must  launch an airplane to recover their wives. By the author of the Jim Nash Private Eye series.