Your sister

You've been hiking this far with your sister, and her complaining is just making you more miserable. The heat has already compelled her to remove her shirt, leaving her curvy body clothed in only a sports bra and a tight pair of booty shorts. You notice more than a few pervy double-takes from male passersby, but she seems not to mind at all. In fact, with the way she smiled at each of them, you wonder if she might actually enjoy the attention. The very idea disgusts you.

You turn a corner, and at long last you see the large, cool lake stretching out before you. Gentle waves lap quietly against the shore in front of you, invitingly. Your sister turns to you and smiles. Without wasting a breath, her small remaining pieces of clothing come flying off and she runs into the water, completely naked. You're not entirely shocked; this is the far from the first time she's done something like this.

You shake your head at her wide, bare ass as she makes her way into the water. Still, despite lacking the confidence in your body that she has, you can't deny that the water looks wonderfully refreshing on her naked skin. You hesitate before you rush in after her.