@Jeole:
We may even have Chiyo finally tell the whole truth to Igarashi xD!
That's what I've been hoping for but, after all this time (92 chapters since Chiyo initially deceived Igarashi by pretending that she was meeting Ookuma for the first time), I doubt that she'll ever tell him. He will most likely find out by overhearing something, or perhaps Ookuma will tell him, or even Yuna, who overheard Ookuma and Chiyo's conversation at the festival.
@Card: If Igarashi had actually told her what happened, instead of just saying "Something came up," would Chiyo have reacted any differently? I doubt it, and I can't blame her this time. Igarashi was a A-class dope. He's got a cell phone. He should have called her, but it didn't even cross his mind. He's gotta get his priorities straight:
girlfriend comes first. With Igarashi repetitively making stupid blunders, it's no wonder that Chiyo would give up hope.