Lol at all the "Ayano is pathetic and conforming". Show me one single panel where she looks like she is suffering, or is sad, or displeased with these arrangements, which she ought to be if she is merely "conforming". She is fully aware Kyouko spends time with Yui, openly talks about it, Kyouko hides nothing from her, to the point Ayano is privy to messages where her girlfriend is arranging another hookup with Yui. And at the very end, Ayano says she likes even this, for a lack of a better word, bad part of Kyouko. "You're a sneaky one", while touching her girlfriend's cheek, as a probable prelude to lewdness, oh yes, she is clearly conforming to hell and back here.
The one who "admitted" Ayano would cry was Yui. First of, by the looks of it, it seems like Yui is unaware Ayano already knows about the whole thing, at least we are not presented with any clue that would suggest otherwise. Secondly, Yui is the only one who genuinely feels bad about the cheating, even though she is clearly unable to stop. Which leads me to suspect Chinatsu is probably the only one in the dark about the whole thing (again, we are not shown anything that would suggest otherwise, and considering how Yui is clearly torn, seems even more unlikely she said anything to her girlfriend). So, my take on this is Yui is the one feeling bad about the cheating, her girlfriend does not know, she thinks Ayano does not know, so of course she assumes Ayano would be hurt if she were to found out. And even then, she did not get much into it, other than one single comment that was clearly more 'shut up, Kyouko, what we are doing is bad', rather than actually talking about Ayano. And how does what Yui says in any way correlate to what Ayano actually feels?
If anything, Ayano and Kyouko seem more like they are in an open relationship, rather than one actually cheating on the other. I mean, is it cheating when her girlfriend knows about the whole thing, does not object, does not look hurt in any way, and the two of them openly talk about it? Again, find me a panel of Ayano looking hurt.
Kyouko clearly enjoys this whole setup, she is obviously in love with Yui, but does not want to risk an actual relationship (according to what she says to Ayano), she likes Ayano (otherwise, why date her), keeps her in the loop, and she does not seem to mind Yui dating Chinatsu (the "putting on a good-girl act" could mean this is not in fact true, but she just looks too chill about the whole situation for me to read it that way, plus, she seemed like genuinely offering to Yui to hear about her relationship woes, which would be strange if she is liable to get hurt by hearing that). Ayano is clearly in love with Kyouko, and I am struggling to see what would indicate she is against Kyouko seeing Yui. Hell, it seems the two of them discussing the whole complicated arrangement lead to a post-end/off-screen sex, so they may even find the whole thing as a sort of a turn-on.
Now, that is not to say there is nothing bad about this, because there is. Even though the two of them seem chill about it, there is still cheating going on, mainly, Yui is cheating on Chinatsu. Kyouko is Yui's cheating partner, so that does not say anything good about her consideration for Chinatsu. Ayano does not seem to mind her girlfriend sleeping with another girl, but she too knows that the girl in question has a partner, a partner Ayano also knows personally. Again, she does not seem bothered by this. Hmm... the more I think about the Ayano/Kyouko pair in this work, the more I like them. I am a sucker for terrible characters, I guess.
Point is, you missed the appropriate character with your description of "pathetic and conforming". In this story, that would be Yui. She is the one who genuinely cheats on her girlfriend, she is the one who feels bad about the whole thing, and she is the one who is trying (and failing) to put a stop to it all.
Chinatsu drew the shortest stick, though.
