Disco Mahjong - Otachidai no Okite
You find women at a local dance club and lure them to games of strip mahjongg. The first victory will win you the girl taking her top down; eventually you get them naked and force them to masturbate. Those scenes have minor animation but aren't very explicit. Afterwards you are rewarded with another picture of them which seems to imply sexual favors from the girls. The game itself is quite simple and often gives you very good hands from the start, as well as offers power-ups to give you better hands.