A man and his wife have been stranded on a deserted island for many years. One day another man washes up on shore. He and the wife are very attracted to each other right away, but realize certain protocols must be observed.

The husband, however, is very glad to see the second man there. "Now we will be able to have three people doing eight hour shifts in the watchtower, rather than two people doing 12-hour shifts."

The new man is only too happy to help and in fact volunteers to do the first shift. He climbs up the tower and is soon standing watch. Soon the husband and wife start placing stones in a circle to make a fire to cook supper. The second man yells down, "Hey, no f**king!"

They yell back, "We're not f**king!" A few minutes later they start to put driftwood into the stone circle. Again the second man yells down, "Hey, no f**king!" Again they yell back, "We're not f**king!" Later they are putting palm leaves on the roof of their shack to patch leaks. Once again the second man yells down, "Hey, I said no f**king!" They yell back, "We're not f**king!!"

Finally the shift is over so the second man climbs down from the tower and the husband starts to climb up. He's not even halfway up before the wife and second man are screwing each other's brains out. The husband looks out from the tower and says, "Son-of-a-gun. From up here it DOES look like they're f**king."