1 definition by Yourtrashkid
A step sis likes to masturbate, the step sis is so clumsy she gets stuck atleast twice a week, no matter where it is, a step bro will always use this opportunity to have sex with her and jack off, you will often hear this sentence follow, "WHAT ARE YOU DOING STEP BRO ". If a step bro catches her masturbating, the step sis can now tell their parents that her step bro watched her masturbating, so she will tell the step bro to have sex with her and she won't tell her parents.
by Yourtrashkid August 6, 2020