The girls had by now shifted positions and were laying on their sides facing each other, their bodies seemingly glued to each other.  Lisa was still vigorously masturbating her sister , her eyes closed in sexual bliss.....Cassie saw their mother staring at them but was too engrossed in their incest love making to try and stop.<br/>Finally Lisa opened her eyes....with her back to the door she couldn't know their mother had by now caught them literally in the act, but she looked at Cassie whos eyes were pointing upwards......<br/><br/>Lisa turned when she heard their mother.<br/>"Oh!......uh, Hi Mom," she said nervously, her voice in panic mode.<br/>"Cassie was asking me how to......uh, kiss so she could......uh......Oh shit......"