It was one day... I thought she was doing her homework, so I peeked in and saw my sister rubbing her clit on the corner of the desk... At first, I had no idea what she was doing... If her clit itches, she should just scratch it with her hand, I thought, but then her face gradually took on a blissful expression and she came... Could this be an orgasm? Was my sister experiencing ecstatic orgasm on the corner of the desk?!
