A B.C. Supreme Court judge granted a Vancouver woman a divorce Tuesday after deciding that the woman's husband had indeed engaged in adultery when he had sex with another man.

The traditional definition of adultery is voluntary sex between a spouse and someone of the opposite gender, to whom he or she isn't married.

But Justice Nicole Garson of the B.C. Supreme Court said Tuesday that she had been persuaded to make a change in the traditional definition of adultery.

The woman, who can be identified only as Ms. P due to a court order, was challenging Canada's divorce legislation after Garson earlier ruled that her husband's extramarital affair with a man didn't legally count as adultery.

The woman had been married nearly 17 years when, last October, she discovered her husband was having an affair with a younger man.

She and her husband separated immediately and she filed for divorce two months later, seeking an immediate end to their marriage.

Her husband signed an affidavit on Jan. 5, 2005, acknowledging his adulterous relationship, and didn't appear in court in February to contest the divorce.

Canada's Divorce Act allows for a no-fault divorce after a one-year separation, on grounds of marital breakdown. It also allows for an immediate divorce if there is admitted or proven adultery or cruelty.

But Garson refused to grant an immediate divorce -- because the definition of adultery in common law didn't include homosexual relations.

"I was completely devastated and I felt like I didn't matter," Ms. P told CTV's Canada AM.

The judge told the woman last Friday that she would hear the case again if a lawyer could argue why the legal definition of adultery should be broadened to include same-sex adultery.

The woman's lawyer, barbara findlay (who spells her name in lower-case letters), argued that the traditional definition of adultery is as outdated as the original common-law definition of marriage, which was based on procreation.

"We argued, and the federal government agreed with us, that the court can make what is called in law an incremental change in light of current circumstances," said findlay, "so that divorce will, from now on, be understood to be available where there is, for example, intimate genital contact between two people, one of whom is married."

Garson's decision is expected to have far-reaching consequences across Canada, said findlay, because of the increasing number of same-sex marriages that will inevitably lead to same-sex affairs.

She added that, because adultery isn't defined through federal legislation, judges hearing similar cases in other provinces will likely be persuaded by the B.C. judge's decision.

"I would expect that other judges faced with the same question would rule in the same way," findlay told CTV.

The Divorce Act falls under federal jurisdiction, but it's administered provincially.

The woman said she realizes her divorce may not come any more quickly through this legal challenge than if she had simply waited the requisite one year and obtained a no-fault divorce. But she said she was doing it to help others who find themselves in the position she did.

"I did it for myself, to regain some control over my life," Ms. P told CTV. "I also did it because I know that there are a lot of people [in the same situation] who aren't in a position to do anything about it, and I was, so I thought I should act."

The woman has also launched a constitutional challenge based on the Charter, saying the definition of adultery discriminates against gay and lesbian couples because it makes divorce less accessible to them compared to homosexuals.