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Miyo created a topic of Love Shuttle

The side stories always give me whiplash lmao
But i have a question, when Do hwa was a teenager he asked his mum if Do Jun was really his brother but her reply text bubble was empty and then she whispered the answer and he seemed horrified
So does that mean Do Jun is really his bio brother or does it mean Do Jun is not his bio brother and the reason he looked so distressed is because he'd been treating Dj like shit the whole time cause he thought they were brothers and couldn't be together anyway thus ruining his own chances in his head
Tell me what yall think