Sharing a room with your little sister is hard, especially since Mom said both of you had to be fully clothed in there. When you forget and walk in in just a towel, your sister says you can either drop it and show off your stuff or she'll get you in trouble. You decide to show her and her reaction is so humiliating! She laughs at your tiny prick, comparing it to her fingernail. She says she'll tell everyone she knows and no one will every want to have sex with you. She goes on and on, laughing at your small dick until she's had her fun and finally tells you to go get dressed.