Responses
Or maybe because he was in rut, he wasn't in his right mind and thus couldn't control his fertilisation? Since they alr said they lose their control over fertilisation if he don't release their pheromones with time
If alpha controls fertilization, then he must want to impregnate Josh that time even though he probably can't for control himself. He might as well at least remembered he marked someone or he simply just didn't care about it at all cause he sleep with many people. It's impossible if he didn't notice that josh an omega and he have an audacity to forget.