I've read enough of these types of manga to keep my expectations low, but I do appreciate the implication of where this is going. From the title of the manga, there's a growing clarity that Tsubaki has always admired Otakei in some fashion, and from the events up till now that the manga he's drawing will be a cathartic joint creation in some manner (he's already taken the admirable initiative to be an 'exhibitionist' with it, basically making a not-Tsubaki character for a coming-of-age story, and she's already participated twice (at minimum) in his creations).
Desire is always non-negotiable, abstract and messy and we'll no doubt get something about how things were in Tsubaki's marriage, but the way every panel between her and Otakei was framed up till now provides the core tension alongside the shots of her wedding ring. The two are constantly framed, but always with a certain distance or contest between them, which might vanish as they pour more of themselves into the manga and by default, each other.
She definitely cared for her husband, but something about how quickly she picked back up the thread with Otakei makes me wonder if there isn't something deeper she's been waiting for. It's to be seen, but the way her sister-in-law acted does seem to imply something was performative or disjointed in or out of the marriage.
Right now she's (drunkenly) overlaying her husband onto Keita, but a poor first step at connection can still lead to connection, and Keita seems to be bit more graceful with feelings than most romance leads. As his past editor said, it's his job as a manga artist to be able to communicate with people, and his handling of feelings was the one compliment he received from his 'rival'.
The title of this chapter was about Keita, but it's ambigious on how much it also applies to Tsubaki. She could just miss her husband, or actually be crushed by regret over something in her past marriage. But it wouldn't be interesting for this drunken mistake to lead into anything than an 'in vino veritas' moment.
Either way, a bond can't be romantic without a firm platonic foundation, which is where we are right now. I hope the author won't drag this one out for a hundred chapters, but I'm not holding my breath.
Edit: Also can't forget that the first chapter said it was about 'those on the fringes of society'. There's evidently some kind of kinship between them.