This was widely interpreted to mean that custody and support decisions should not depend on who cheated first.
Mr. and Mrs. Leskun married in 1978. They met while they were both working in the bank. She was ten years older than him, already married with two children. She financed his MBA and Certified General Accountant certification. She continued to work in the bank. Fourteen years after Mr. Crosbie's bill, Mr. Leskun had an affair, asked for a divorce and married a younger woman.
Mrs. Leskun took it badly, and is no longer working at the bank. Mr. Leskun thought she could get back to work, become self-sufficient and reduce the burden of spousal support.
Justice Southin sized up Mrs. Leskun as someone who had "made the litigation her life" to get back at Mr. Leskun. Southin was too honest to deny that the excusableness of this course of action turned on who had screwed around. She couldn't have sympathized with a woman in Mrs. Leskun's position who had decided to find herself, or run with the wolves, and asked Mr. Leskun to pay for it. She could sympathize with a woman scorned.
The SCC has left Southin's result in place, but without the moralizing. I understand their desire to follow the statute, and Crosbie's ill-considered plan to banish human feeling from divorce. But the result is a mess. If Mrs. Leskun had run off with her yoga instructor, and made the same demands she does, the world would howl in fury. But if Mr. Leskun wishes to exercise the successful accountant's privilege of late-life serial polygamy, then the least we can do is force him to internalize the externalities.
Case Comment of Leskun v. Leskun, 2006 SCC 25.