Remember, Asuka had finally confessed, and Ayako had accepted her feelings (more or less) and agreed to have romantic kisses and share a bed with Asuka. Things were looking good... and then, at the very last page of a chapter, Akira appeared for the first time: she was at the airport, freshly arrived to the city, and was calling Ayako to say: 'Hey, darling, I'm back in town. I'm going to your place. I'll be staying with you. I love you.'
Nope, that was actually Akira staying at their house which caused them to share a bed again which led to "a talk" between them which led to their kissing agreement. So Akira propelled their relationship rather than delaying them.
You know you aren't refuting anything, right? The OP could have said: "Asuka had finally confessed, things were looking good... and then, at the very last page of a chapter, Akira appeared for the first time: she was at the airport, blah blah..." and it wouldn't have changed a thing to the point.
And as for Akira propelling their relationship, well duh: that's what every ex-who-returns ends up doing in every romantic manga ever. No matter what her plans are, her actions always end up making the main couple stronger. Even if, like Akira, they don't wish for such a development.
That's how the "ex who returns" always appears for the first time. Always when things are going well for the MC couple. Always a dramatic appearance in the last page of a chapter, where she reveals she's back to rekindle the old affair. It's like a law of manga or something, hehe.
This manga showed quite a few times already that it's not following usual tropes. Or rather I think Taiyki enjoying trolling readers with promises of such tropes only to gloriously avert them.
Gross generalization, very inaccurate. This manga follows tropes or not, according to whatever the author decides it's best for the story. I can give you a list of tropes from TVtropes that can be found here, if you want.
Ayako said that Akira can LOOK at her in such a way, not FUCK her because she is used to this.
This is only your speculation, don't present it as fact.
Akira said she wanted oyakodon, that is, fuck Ayako and Asuka together. Ayako said "Don't ever look at Asuka in that way." Then, in a 3d panel, she added: "I don't really mind if it's me, though." What is she referring to, the "look" from 1 panel before or the "fuck" from 2 panels before? I always assumed she was talking about fucking, and, from the previous comments, it seems I wasn't the only one who read the scene that way. Frankly, it had never occurred to me, until I saw your message, that she could be talking about looking... but I'll give you that such a reading works, too (even if it appears like a silly thing for Ayako to say).
I don't think Ayako is a kind of woman to just casually have sex with her friend/sister-in-love. If she had that kind of relationship with Akira she would treat it seriously.
I see them very well comforting each other after their loss. For Akira, it would mean a lot; for Ayako, it would be just a healing thing: two girls who have been hurt healing each other through the physical expression of love. Eventually Ayako would decide to stop, and Akira would have to agree. Akira, aamof, doesn't want to go serious with Ayako, for reasons of vague guilt that are not clear yet, but she obviously has no problem with a casual tryst.
And for Akira... the woman saying stuff like here
https://dynasty-scans.com/chapters/1_x_ch08#25
Yes, that's exactly what I was taking about: vague guilt the details of which escape us still. Akira being Akira, that doesn't stop her from trying to steal kisses from Ayako or making sexual propositions. This is canon. And think about this: it's also a reality that Ayako understands lesbian attraction and accepts it as normal, whether she's the one feeling it ot it's someone else feeling it for her. Looking at her interactions with Akira, isn't it natural to assume she was taught by her?