Three Caves-Fool joke

In the Amazon rain forest, three explorers were walking. One was Irish, another English, and the last American. Soon, they came across a tribe, and the leader of the tribe told them that if they wanted to pass through this territory, they had to pass the three caves test. The explorers agreed and asked what the three cave test was. 
The leader of the tribe took them to the caves, where he said, "Inside the first, there are three bottles of rum, each 100 years old and said to be toxic. You have to drink one each. In the second is a lion with a thorn in his foot. You must remove the thorn. In the third is a woman who has never been satisfied, and she must be satisfied." 
The three men were hesitant but could not back out, so the American went into the first cave, drank the bottle, and died soon afterward. The Englishman was second. He went into the first cave, drank the bottle, then went into the second cave. There was a lot of commotion and roaring. No one emerged from the cave. 
Lastly, the Irish man went into the first cave and drank the bottle. He went into the second cave. At first, there was a lot of commotion, and then there was a soft purring sound. Then he entered the last cave. Two minutes later, he came out puzzled and asked, "Where's the thorn in the woman's foot?"