How to Steal a House Cat

Minato Chida is a janitor in an office building and one day he gets caught up in the raunchy adventures of a gay couple. But, the lovin' he gets feels so good that he becomes unable to forget Chiaki, one of the guys he hooks up with. That's when Mr. Sakaki, the supposed boyfriend of Chiaki, asks, "Want to have some more fun?" and invites Minato to join both of them in bed...! This is a yaoi story full of group affairs and debauchery!

(Source: Renta!)