Getting pregnant is the worst thing that could happen to Moryeon, Mr. I wanted to pretend to be an alpha to usurp the title. Want it to happen just to see him suffer lmao. The 4th and 5th would be fitting omegas ngl could it be that the oldest brothers never exposed their alpha pheromones and the younger ones are too sheltered to have them exposed to them (Yeju notes in chapter 1 that Moryeon clearly was never exposed to alpha pheromones on purpose) so it could be possible. I've seen however people theorize that the 6th is a potential alpha which is fun

I know there's A LOT going on right now besides the main couple having a kid, but it kinda fits, doesn't it? The omega is hiding his status to his family, and he's sleeping with an alpha. If he gets pregnant, that's a huge secret to keep. Also curious if any of his other siblings are hiding an omega status.