You do know this is omegaverse right? Doyun isn't having sex with Tae bc he wants to, it's bc when he goes into heat he's acting on instincts not rational thought.
Also he has been living comfortably as a beta for 26 years then this rival coworker's pheromones activate these horrible heats..(pain, nausea, hot flash) and he is in this new full on omega mode. Now he doesn't even know his own body when he is exposed to Tae's pheromones;who wouldn't run away from all that and want to go back to being more beta than omega? I think he is hoping that by physically distancing himself from his omega trigger..i.e. Tae he can go back to being 'normal' so that would men not dating him. But don't worry the spoiler comments say things wilk progress eventually.
Why are you freaking rejecting him! I don't freaking understand you guys did it and be was saying the truth about you guys needing to talk about it! I mean who the freak sleeps with a dude multiple time aware of it and then just running away for no apparent reason. I mean the dude is a good guys as well!