What indications in the story prepare us for the eventual breakdown in the relationship?
I think that we get some fairly distinct indications that the relationship between both Shoba and Shukumar is in trouble. It is evident that some point has been passed in which an eventual breakdown in the relationship can be perceived. From the earliest moments of the exposition, this is seen. When the notice of the electricity being cut is countered by Shoba to "do this sort of thing during the day," Shukumar response with the rather emotionally taut, "When I'm here, you mean." It's a line that indicates an emotional disconnect between both. His own lack of care about going out or even brushing his teeth is reflective of the disarray he is enduring. His dissertation is not finished and he is driven more by the demons of guilt that he was not there for Shoba at the critical moment. The emotional disconnect is reflective in the description of Shoba during to counter his own introverted nature:
He hadn’t left the house at all that day, or the day before. The more Shoba stayed out, the more she began putting in extra hours at work and taking on additional projects, the more he wanted to stay in, not even leaving to get the mail, or to buy fruit or wine at the stores by the trolley stop.
Such a description is an early indication that the condition that both share at this point in their lives is one of disconnect, almost like passengers in transit as opposed to a couple committed to being with one another as one. The fact that she no longer prepares meals and that she is more absent in being with him is reflective of this. She eating by the television and he by the computer helps to further illuminate that the couple is heading towards some type of eventual breakup. I think that the entire game of confessing something never told before is a progression towards an ending of the relationship, something that Shoba had envisioned herself. It is here where I think that that one can see that the glimpse into their relationship is one in which their union is headed towards an eventual end.