A few points in order of personal importance:
Despite how quickly she turned from heel to face being a bit of a whiplash, big fan of how open she is about it and especially her decision to open up to her friend.
Big fan of the friend's response and supportiveness, even bigger fan of her actual best friend responses™. That "eat shit and die" was bond-stronger-than-steel type response.
That said, something got into my head that Yui is also a potential love rival in disguise and I'm having trouble shaking off that angle lol.
That final panel was top-tier friends banter, but also Kaidou is ruthless. Can't really think of anything other than "eat shit and die" to respond to that lol.
With how many times they said "it's mutual" I'm worried that shit's gonna happen. I have trust issues. Though I don't expect things to go too badly either way.