An English Joke

Dear friend, I'd like to share a joke with you today.

A soldier wanted to ask for a leave from his commanding officer, so he said he would go to attend his sister's wedding. The officer asked him to stay outside the office and he wanted to consider the request. Several minutes later, the officer let the soldier back in and said to him:"You are such a liar. I have phoned your sister and she told me she is already married."
Then the soldier said angrily:"You are a even larger liar! You couldn't have phoned my sister  because I don't have a sister at all!"