
lol out of curiosity, because i saw a fanart where shaia and hugo as adults are dressed in suits with an adult theo (threesome hinting and gaming) but i always thought that shaia was a girl, so i just wanna ask if i thought wrong the whole time.......

It would seem that anyone can get pregnant in omegaverse, but betas can't be bonded. If you mean Theo, it hasn't been mentioned if he's omega or beta anyway.
From what I understand in this particular series, alpha beasts have very low birth rate which is why, so far, they have mated with the highly fertile human omega. Still, it doesn't rule out the possibility that a beta can bear beast children given the right circumstances... ;)
In any case, thanks to their parents' example, the twins would probably bond/mate for love. Would be VERY interesting how a soul bond plays out on a threesome!

Well, from another comment that I've read, it's logical to assume Theo is beta, because his family has served the Siegfried family for generations, and most of the servants (Horan and Baron, for example) are beta. (However, Kai is an omega from an alpha bloodline, so it can probably go either way.) Theo is most likely still too young to determine his secondary sex.
On a completely unrelated matter, there's a scene where Theo is carrying one of the twins in his arms. I wonder which one that is.

Kashikomarimashita, especially Miyauchi's story arc, is one of the few omegaverse stories that specifically mentions pregnancy for male alphas and betas as well. It also shows an alpha choosing not to bond with his supposed soul bond.
http://www.mangago.zone/read-manga/okusama_ha_alpha/ has two alphas pairing, apparently, either of them can get pregnant. I do remember vaguely another BL manga where a male beta can get pregnant. Will have to trawl through my faves...
This particular beast series is a lot more vague about it, saying only that everyone can mate and that only Omegas can birth beasts: http://www.mangago.zone/read-manga/pendulum_kemonohito_omegaverse/nmt/c001/7/
What would probably be more interesting is if Theo is an omega and bonds with one of the twins, how would that affect the other twin who shares the exact same alpha DNA? (but as already mentioned, it doesn't make sense for an omega to be working as a servant to two alphas).
WILL!!!! Don’t you dare do anything shitty cause I’m rooting you for Julio goddammit!