Snake and love

A poisonous snake is so cold. She begs a young man to put her into his pocket to warm her up. The young man says: "you are a poisonous snake, you will bite me after you get warm." The snake replies: "I won't bite you, please put me into your pocket." The young man still refuses, but the snake begs and begs. Finally he put the snake into his pocket. After she warms up, he gets bitten. The young man asked the snake in pain: you said you would not bite me, why do you do it? The snake says: you know I am poisonous but you still put me into your pocket. It's your mistake.