Why did you start laughing?

One day in the forest, 3 guys were just hiking along a trail when all of a sudden, a huge pack of people attacked them and knocked them out.

When they woke up, they were at the leader of the tribe's throne.

The chief then said "All of your lives may be spared if you can find ten of one fruit and bring them back to me."

So after a while the first man returned with 10 apples. The chief then ordered him to stick all ten of them up his butt without making any expression at all on his face. He had a little bit of trouble with the first one and started crying while trying to put the next one in. He was soon killed.

Later, the next guy came in with 10 grapes. The chief soon ordered him to do the same as the first guy. After to the 9th grape, the man started laughing so hard for no apparent reason, and was killed.

The first two guys soon met in heaven and the first guy ask the second, "Why did you start laughing? You only needed one more grape and you'd have gotten away!"

The second guy answered while still laughing, "I couldn't help it. I saw the third guy walking in with pineapples.