Suezen Kurau wa Otoko no Tachi据え膳喰らうは男のタチ; It's Man's Nature To Eat What's Served

Sera, a sexually curious salaryman, has newly set his sights on Ryo, a new employee at his favourite bar. He tries to talk to him about sex, a new kind of pleasure, but Ryo is popular with men and women of all ages and has a lot of experience. But he can't catch on, and when he pesters him, Ryo gets mad and teaches him about the pleasures of the backside...