Pride and accomplishment
The novel shows that Vimbai's pride is at other people's expense. She feels she is better than others because she has a good job, but she doesn't see that there is another way to be proud without disparaging the less accomplished or less fortunate. When Dumisani arrives, she is struck by his people skills. She learns that there is a way to be proud of one's self while also being winsome and sociable (dramatic irony).
The non-romantic roommates
Suddenly, Vimbai and Dumisani are roommates, and they work closely with one another, so they are fast friends, but Vimbai wonders if they are becoming something more. Ironically, a romantic relationship never blooms, and she is beside herself trying to figure out if there is something or not. Her arrangement was platonic, but she can't help but wish he would return her affection. The situation is not yielding what she had hoped.
The ironic wedding
Weddings are typically about family unity and new connections, but this wedding is ironically divisive in Dumisani's family, and as Vimbai realizes bitterly, there is no hope for new connections between them—even though his whole family thought perhaps there would be. She struggles to understand why this would be the case between them, until she finds the diary where he writes about secretly being gay. The family hoped his date was his girlfriend, but Vimbai realizes she will never be his girlfriend.
The intimate diary
For Dumisani, the diary is not just a place for him to write his daily reflections. It is the substance of his loneliness. He must talk about his struggles with someone, but no one wants to be in community with him, because his community has closed-minded beliefs about homosexuality. This leaves him in a painfully lonely space, so he journals out of desperate desire for community. The diary is a lonely form of companionship to him.
Vimbai's lesson in empathy
Vimbai mistreats Dumisani when she realizes that he is gay, but she doesn't even really care necessarily about what the reason is that she isn't getting what she wants; it's mostly just about her not getting what she wants. She slowly starts to realize that her friend has a more painful, difficult life than she could understand, and although she can empathize with his loneliness, she still just wants what she wants. The irony of her failure to empathize is that she claims to want love, but she isn't offering love. She is offering judgment.