Responses
Idk if u r talking about this: The Alpha's Bride
I think i know..
I was also thinking of alphas bride
Its BEAST OF BLOOD..
3 brother.. Wolf, vampire and siren.. They so fucking hot
This manga is omegaverse (i think) anyways, it has a 3rd party gender and the mc's mother got engaged to a wealthy single father with 3 sons (i think the 3 are alpha, beta and im pretty sure the 3rd is siren) the story goes on where he was introduced to the youngest (siren) bcs his other brothers are not around. Then after many talks he guided the m to their campus which are 3 separate buildings one for alphas one for betas and one for sirens. Long story short he met the second sibling in a building sleeping and when he got closer he pulled the mc.
I'm sorry but a quick reminder is I'm not rlly certain if it was alpha and beta but im 100% sure about the siren and also when the mc was introduced to the youngest(siren) he was in a big pool and also the pool was at the top of a building.