Looking for a title

Hopefully someone remembers but I'm trying to remember this yaoi title I read a couple of months back but can't remember so the uke can see and experience the seme's sex fantasies.The semester is like the most popular guy at work and seems super serious but is always having the most graphic sex fantasies about the use at work and the use experiences in real time so he is always leaving meetings and eventual discovers that for the fantasy to stop for a while he has to have the use come inside him or be near him can't rember which hopefully someone remembers this title also they where like high school rivals or friends at first and reunited at work