Step Sis Tricks Gullible Younger Sis Into Anal Play

I'm a bit nervous about going to high school, but my older sis audrey is there to reassure me. she knows what i can do to make the boys like me - use my arsehole! apparently all the girls do it and it feels much better anyway. she kindly offers to show me what to do using her gloved finger and then a toy. i realise just how right she is and we decide we are going to turn this into a regular thing...