Soukan Yuugi
English title: Sexual Pursuit
Japanese title: 相姦遊戯
Type: OVA
Source: Visual novel
Episodes: 2
Status: Finished Airing
Aired: Aug 10, 2007 to Nov 9, 2007
Duration: 27 min per ep
Rating: Rx - Hentai
Studios: Y.O.U.C
Producers: Digital Works
Licensors: Media Blasters
Genres: Hentai

Yuji just got himself a new board game and he can't wait to play. What Yuji doesn't know is that the game possesses secret powers - sexual powers, to be precise. He and his stepmother decide to give it a try. The game requires drawing cards from a deck that have sexual instructions on them. Though it starts out innocently enough, Yuji soon experiences sexual feelings for his opponent. As the game progresses and the sexual tension escalates, it culminates in a sexual free-for-all with his stepmother and stepsister. 

(Source: Boxtorrents)