Big sis and her little brother bonding by masturbating together. Arms linked together as they get themselves off. No touching allowed to keep it from being weird
Big sis gushing as she showing him her favorite porn. Little bro thanking her by 'accidentally' pointing his cock at her when he cums
When your sister comes to your room in the middle of the night, she makes sure that your parents won't hear. No matter what she does and how loud you are.