A Frigid Night's Carnal Temptations

Riku has a hot, busty girlfriend named Sayo, which sound fantastic, but there's one issue... She's part succubus. Normally, Riku takes care of her urges himself with some kissing, so this isn't the biggest deal, but when Sayo gets caught in a blizzard alone with one of Riku's buddies on a ski trip, she has problems fighting her inner nature.