Most bisexual ppl like both genders but has a preference for a specific gender. Some ppl are into both but prefer the same gender while others prefer the opposite gender. Some ppl are both romantically and sexually attracted to both gender while others might be romantically attracted to one gender and sexually attracted to another
If we were to talk about both characters in the manhwa, I highly doubt either of them are bisexual. It seems like when they switched bodies, it was only natural to have these reactions from both ends. I highly doubt the dude would even let serin switch bodies again let alone peg him, even if it felt good

		
So if anyone has ever been confused whether they are bisexual or not... I propose THIS as an official standardised test used in doctors office.Just a couple of chapters should do wonders for the indecisive ones.
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