I’m so confused about Inho... like when did he and lee bin’s dad get together???

way back when hwa gok was first trying to become pregnant. inho used his pheromones to put him into heat.

the author didn't say in details in which part they got together. in season 1 ino tried to kill yibin, vampire daddy saved yibin, and he said he'll deal with ino. then suddenly in season 2 they're fucking lol