Two couples go away for the weekend. The two blokes, Jack and Bill, try to persuade their wives to do a bit of partner swapping for the night. After several drinks they succeed. Jack knows it’s that time of the month for his wife and the thought of Bill not knowing this makes him smile. The guys agree that when they sit around the breakfast table the following morning, they will tap their teaspoon on the side of their coffee mug the number of times they did it with each other’s wife. Clever enough! The next morning they are all at the breakfast table, slightly hungover and quite uncomfortable, when Jack proudly taps his teaspoon three times against his mug. After pausing to gather his thoughts, Bill takes his teaspoon, taps it once on the strawberry jam and three times on the Nutella.