My lover's mother is extremely horny

Keiran Lee's wife has no choice but to bring her former schoolgirl sister, Karma Rx, who is passing through town, thanks to their family's code of honor - which is binding for life. With Keiran's wife being the pinnacle of prim and proper conservatism, Keiran expects more of the same from Karma, whom he's never met. But when Karma comes down for dinner, she surprises Keiran in a completely unexpected way - thanks to planning, a shocking outfit, and encouragement from his wife.