Who is the ass?

A plane crashes on an island. The only survivor is a man. There is enough food supplies and water on board to sustain the man. He goes all around but does not find any living thing other than a donkey. The donkey follows the man to the site of the crash and continues to stay there. Many days pass by. One day the man starts feeling frustated sexually and decides to use the donkey for satisfying his urge. The moment he goes behind the donkey, the donkey realising what was going to happen kicks him. He tries it again and again with the same result. The man would not give up and days pass by.Many days later another plane crashes on the same island. The lone survivor is a beautiful woman. She realises the man's predicament, and her own, very soon. She approaches the man and says, "I would do any thing for you, anything. You can use me whatever way you want. Just say it". The man ponders over it. Then he takes her along to the donkey and says, "Don't mind it, but could you please hold this donkey's legs".