This topic may contain spoilers
Well, the uke and the seme are in a fwb relationship, with the seme being in love with the uke while the uke in love with another third guy whom with which also has a fwb rel but it's more complicated than that..the seme is aware of all this. A lot happens and at some point the uke fcks the third guy, his love interest, all while making a promise to the seme to go see him...which he does after. So it's not technically cheating since the uke and seme are just fwb but with a little more feelings involved.
It sounds crazy, I know, but it is a really nice story

Is there cheating here?