Newly married Kate England visits her chiropractor sister-in-law Melissa Moore for advice that can hopefully save her marriage. Her sex life has been practically nonexistent since her husband started suffering from back pain a couple of month ago. Melissa suggests trying a positioning device for coitus, called a sex wedge. Similar to a bolster, the durable triangular cushion is the perfect body prop for people with weakness in the lower back. It helped her after her accident. She brings Kate to the bedroom and puts the wedge on the bed. When Kate stares at it apprehensively, Melissa warns her of what will happen if she doesn't fix her problem. She knows her brother. He'll get it elsewhere. He'll give up on their marriage before he gives up on sex. Kate is nearly in tears at the thought of him cheating on her. Melissa convinces her to try out the wedge. Kate lies on the bolster elevating her ass, but Melissa wants to show her how to use it. She talks Kate into taking off her romper, whips out the oil and massages her sister-in-law's bare ass. She pulls off Kate's panties inviting further exploration then takes off her clothes, because she doesn't want to stain them with oil. She parts Kate's buttocks suggestively and expresses what she plans on doing to her with her words and with her tongue. Kate isn't entirely comfortable with cheating on her husband, with his sister. She had her experience with women before getting married. But once Melissa starts sucking on her boobs, she has trouble drawing the line. When Melissa plants her warm wet mouth on her sex deprived pussy, Kate cums in no time. Melissa climbs onto the wedge and asks her to reciprocate. Kate obliges her sister-in-law and makes her cum hard in her mouth. Melissa puts Kate into tribbing position and grinds her juicy pussy till she cums!