My stepsister expresses her desire for my penis and arouses my sexual desire

My stepsis has always been a bit of a mystery to me. I\'ve never been sure what she\'s thinking or feeling, but lately, I\'ve noticed a change in her. She\'s been acting a bit more... Interested in me. And I can\'t help but think that maybe she\'s into me. So, I decided to take things a step further and see if she\'s really into me.