I feel like ego plays such a big part in love island. KC got his ego bruised when that door was empty and he been locked in ever since. Meanwhile Kayda picking Zach over stroked his ego and now he’s being sooooo weird about it. Remember how Nic felt about Elan
That "bromance" is also a very sad dynamic. Zach feels like hes better than bryce and finds bryce to be a non threat and he also feels bryce is the only guy willing to engage in his dl homoeroticism. You couldn't wait to tell ppl ur villa bestie was abt to go out sad with kayda.