
I thought maybe the doctor was an omega when I saw Doyun's reaction when the doctor came into the room when D & T were in bed. Why is he suddenly so possessive towards Teahan if the doctor is an alpha? I know it's a sort of animal reaction, as the doctor says, but I found it odd, then he never feels Doyun's pheromones.

It will be good if that was the case, he can pair up with Dojun then. But why would he lie to Doyun, and probably everyone else? Unless maybe he is also a late bloomer.
P.s: As to an alternative as to why Doyun became so possessive, maybe he would have acted in the same manner irrespective of who came to disturb them.
Looking forward to his side of the story.
I think I know why the Doctor can be perfectly fine around omega patience. He's an alpha's alpha, an alpha lover. So omegas pheromones don't affect him. So now the only one that's needs to worry about him is Doyun's big bro. Maybe it's just pheromones don't bother him at all.