now remember that douchebag seme from http://www.mangago.zone/read-manga/romantic_joutou/ ?? remember how he had like fuckn douzens of omega bonds? i think in this author's omegaverse, you can have as many omega partners as you want. so in response to your question, once Towa is bonded with Seiji, Seiji will still be bonded with Aiji. and, Aiji orchestrated the whole thing so that Seiji would have a new bond leaving Aiji behind. Aiji was basically insecure that Seiji would leave him for another person one day so he thought it would be better done early than later. this could also be reworded as Aiji being forever bonded to Seiji but never anyone else. Seiji could bond with anyone & Aiji would be left out bc of the bond he can't break with his brother (which obviously didn't happen, thank god). sadly, the twins are related to that douchebag seme in Romantic Joutou (⊙…⊙ ).
Wait--They are? I didn't catch that before! Thank you!
Well, this was interesting. I'll admit the twincest bit was a off putting at first for me, but I ended up really enjoying the plot.
One thing though. So at first I thought only one of the twins had the gauge piercings so it was all cool, it was a way to tell them apart. But nope, they each had one gauge piercing on one side/same side. Theeeeen it just bothered me that the piercings were uneven, really didn't see the appeal of having a guage in one ear only. ┑(￣Д ￣)┍
Aside from that, the main thing I was wondering about was the bond.
(Possible spoiler)
If Seiji bit Towa, would that break his bond with Aiji? If so then that would add a whole new layer of complicated. But I was thinking maybe that's the case and it bothers Aiji and maybe why Towa never seemed to completely agree with the idea. These smaller details tend to vary in omegsverse so it's hard to tell without clarification within the series.