Heisenberg's Uncertainty Principle/Schrodinger's Cat Couples engaged in a romantic relationship usually have large amounts of physical contact with one another. However, when someone seems near, physically, to them, they begin acting normally again, even if blushing a bit. We therefore see that the couple has a probability wave function associated with them. Whenever an observer goes to see what they're doing, their wave function collapses and becomes a stable state. This is exactly the same concept that is illustrated in the Schrodinger's cat thought experiment. In this case, a cat is placed in a box along with a Geiger counter, a bottle of poisonous gas hooked up to the Geiger counter, and a radioactive particle source. If the source decays and triggers the counter, the poison is released and the cat dies. However, if the source doesn't decay, the cat lives. This is only a thought experiment, and no cats have ever been killed in one of these experiments. However, be that as it may, you have to open the box to see if the cat is still alive. If you do this, however, you collapse the probability waveform into one of two states: either the cat is alive or dead. While the box remains closed, the cat could be either alive or dead, but once opened, the cat has to choose a state. Just the same, the couple in question may or may not be making out, but when approached, they either will or will not be doing so.