It's just my theory tho
But I think yuuma isn't an omega but he's in love with ML
By some incidents his brother yuuma (ran away one) and the alpha might had heat together and slept together. Then twin brother got pregnant and left the child after birth and ran away. Later yuuya started to take care of the child. And I think that alpha doesn't know about this or he doesn't know about twin brother.
Everything correct alpha seme always liked alpha uke it's Mutual but omega ruined it
I think the alpha knows, theyre twins but i think they gonna have different omegas scented
Oh damn
I just noticed after someone pointed it
The MC name is yuuya
But in id it's yuuma
So the child is probably his twins
And the twin probably abandoned the child and ran away
So yuuya is currently taking care of them as his runaway twin brother
Idk it's just my theory tho
But I think alpha probably don't know about it? Or maybe knows?