Duty Free - Season 1 (1984)

The couples join a coach trip to the mountains, where David buys Linda a gypsy shawl she has admired, but when Amy finds she has lost her money, he sells his watch. Noticing the shawl on Linda and the watch not on David, arouses Amy's suspicions, causing David to claim that the shawl was actually for his wife. When Robert buys Linda another shawl and David feels the need to buy one also as compensation for Linda, David passes off the surplus shawl as a gift for Amy's mother, but Amy isn't convinced and takes artistic revenge on David that leads to trouble in a German ...

After Amy learns that they had a moonlight swim together, Linda and David must find new ways to meet, so Linda devises a system involving towels on her balcony to telegraph to David when it is safe to come up to her room. Robert now knows that his wife has a lover but suspects an innocent Frenchman. Amy, on the other hand, knows precisely what is going on and switches the towels to land David in trouble with a German couple.

David refuses to go with Amy to visit the ruins, saying he already booked a court to play tennis with Linda. Robert still does not suspect, though he looks down on David anyway, seeing him as a social-security scrounger holidaying at taxpayers' expense. With Amy off to the ruins and Robert on the golf course, the loved-up couple move from the tennis court to the bedroom to indulge in a little afternoon delight. But Amy walks in while they're kissing and takes her revenge with hot tea and sticky cakes.

Their affair now out in the open, David and Linda plan to run off together. Robert wants to fight David, but Amy uses subtler means: filling her husband's suitcase with hotel property to get him arrested, then persuading Linda that she had a lucky escape as he is a notorious kleptomaniac known as The Weasel. While Linda happily returns to Robert, Amy--though she has squared things with the police, fails to tell David, subjecting him to further humiliation as he tries to flee the hotel in drag.