I think he realized that he had knotted
Lol it's because if they aren't careful he can get pregnant and uhm that sure as hell wasn't careful (≧∀≦)
Spoiler
Because he knotted him, he didn’t intend to knot him and it was a belated realization of what he had done
Because he is knotting and changing without realizing it. When he comes to his sense its already too late. Before that he never knotting, not even realeasing pheromons during sex. Thats why he is shocked that he do that all instinctively even though he is golden alpha
What happened at the end ??? Why did he make this face ??????? I don't get it please explain or spoil me