So it seems obvious the kids are twins, but I suspect the ML is a twin himself, and Qin Tian's "revenge" is a…
Now that you say this, I can see it 👏🏾👏🏾👏🏾 I’m gonna add to this. I think that the main character’s siblings are the real parents of the kids. All those random flashbacks of that girl have to mean something. Or Hao Yu’s ex is Si Le sister. That the reason why he can’t tell her who Xing Chen’s mother is and why they have the same pin.
1) that guy who is the antagonist is so weir for being all HoaYu’s ex’s back
2) if my theory is correct that so weird haveing relations with someone your sibling also had relations with