I remember it for sure was office/coworker manga. this girl who doesn't want an actual relationship wants to hook up with I think was her coworker. Catch is that he is "chaste" aka doesn't wanna do the deed until he's married. Out of what I remember she had a friend that she ranted to maybe nicknamed "kitty" as the contact's name. I didn't read all of it so i'm not sure if it ever got to smut.