@marmot I mean there will be an actual reversal of roles, as in Yui will be the ‘Mistress’ and Tsukasa will be the Roper.
I think Yui will be traumatized because Tsukasa’s going to run and leave her alone. Cue time skip. They’ll meet when they’re adults and Tsukasa will be the one into the art of Kinbaku because that will be her essentially coming into what she really wants, which is not someone to bestow affection to, but someone she can control. It’s what sets her apart from Yui who wasn’t tying so she can assert her dominance, but was doing so for praise and approval. When they meet again, they’ll be the same. Yui will no longer be the approval seeker because of the trauma Tsukasa’s disappearance will cause. Yui will ultimately want to control Tsukasa and become her ‘Mistress’ so she can keep her forever.
Maybe I’m reading it wrong but Kinbaku seems to be more Tsukasa’s cup of tea than pet play because it’ll side step the grooming/caring that she puts into her pets that later on disappoint her.
All I know is after the bridge outing, Tsukasa accepts that she and Yui ‘are not the same’ and that, along with the fact that she got caught (again from what it seems like), will cause her to turn away from Yui.