The ex telling his story, or rather his story about Keiko, was what flipped the switch and put Ran into active mode. If the ex show up again, I expect it'll be in the context of Keiko putting her past to rest rather than to get back together with him again.
Best case scenario, she tells the ex she has someone new in her life.
Ah, that's certainly possible. I hadn't really thought of him as a trigger rather than a plot point waiting to be revived, but it's true that when Ran next appears, this and this and this sort of thing starts happening, then you have the yuriffic chapters 25, 27, and of course 29... In fact the only chapter since the revelation without any subtext is probably chapter 28.
I also doubt she'll get back with him, whether she gets together with Ran or not; her past has always been portrayed as something which has weighed on her in an unhealthy manner. I don't know too much about her relationship with him, though, so it'd be nice to learn more about it, if only to see how he compares with Ran.
I swear that Shou is making all this recent chapters in order to later say they were straight, come to this forum and laugh at the meltdown?
Wouldn't that be career suicide?
I'm pretty sure he's more than aware of the following this has with yuri fans.
Yeah, you should see the comments on the official site. They're divided into the people saying that the stretching on page 3 is hot, those who say it's nice and cute, and those who are all YURI!! about it. Categories two and three can presumably be assessed as positive reactions to the yuri element, while category one is rather small and therefore near-negligible. I've only seen one negative reaction - the person said that it was the worst and most disgusting chapter - but it might have been trolling, you never know with the Internet. All in all, that's a really large percentage of people who approve of this development, which suggests that they were probably open to the pairing beforehand. Career suicide indeed.
"we haven't shared a futon in a long time"
So they slept together before? When? Why didn't Shou show?
Ahh I noticed that too! I'm guessing it must have been after they moved in together - they would certainly not have had the opportunity to do so while still in school, as Ran makes it quite clear they did not meet beyond bumping into each other in the morning, at school, and in the library.
And to carry on the discussion on to what extent Ran's feelings were shown before this chapter, here are two examples I came across which don't feel like fanservice which haven't been raised yet:
1. when she tries smoking Keiko's cigarettes in chapter 16 - her expression is quite serious, so it doesn't seem like simple curiosity, especially since only three chapters later she starts talking about how disgusting a smoker's lung is; perhaps she wanted to understand her better by doing so.
2. there's another moment in chapter 18 where there's a slightly odd change in atmosphere when Ran starts talking about how she and Keiko used to talk together; it feels sort of wistful to me.