You can actually pinpoint the *exact* moment Vi falls for Cait. It’s right here:
Ekko drops the bomb on Caitlyn that the Enforcers are in Silco’s pocket, which of course she was clueless about.
Vi steps in, because to her, Caitlyn is just a naive rich girl who doesn’t know how things are. She’s honest, if nothing else.
She expects Cait to keep denying it, to fight back, to place all of her trust in the authority she is a part of (because Topsiders trust Topsiders). And then Cait does this:
She doesn’t fight. She doesn’t protect her ego. She doesn’t make demands, she doesn’t assert her Topside authority. She *pleads* with Ekko to let *her* help *them.*
And Vi? This is how she reacts:
She sees Caitlyn for who she really is.
It’s no coincidence that, after this, Vi stops tossing acerbic witticisms at Cait. It’s not that situation got more dire; Vi has already shown a willingness to quip and snipe, even when she’s heavily wounded or when they’re both captive and chained up. No, it’s because she’s not trying to prove she’s better than her.
It’s also when she starts to initiate touch, or at least reciprocate affection touches. She lets herself be soft around her because she knows it’s safe to be.
The only people Vi ever trusted that much were Ekko (barely), Vander (barely), and Powder.
Cait, just being herself, convinced Vi to let her in when she wasn’t trying.