The men: we (all) wear jeans, tight t-shirts.
The women: you (all) wear tiny black dresses, black thongs, black thigh-highs, black shoes.
There are four couples. We’ve never met.
We gather for drinks at 9 pm.
The men talk in one group. And assign the numbers “1” to “4” to each of the men.
The women talk in another. And assign the numbers “1” to “4” to each of the women.
The two groups don’t interact.
At 9:30, each group’s number “1” excuses him- or herself and makes her or his way to the bathroom. No more than five minutes later, they return. The two “2”s do the same thing. Then the “3”s, and then the “4”s.
After the “4”s return, the two groups merge, and decide whether to adjourn to a hotel room together.