Their safe words were “Tweety Bird,” meant to indicate their admittedly kinky sexual behaviour should stop.

And they are what the common law wife of a man known as “J.A.” said she uttered sometime after waking from unconsciousness and finding herself being sodomized by her partner, who was later convicted of sexual assault and breach of probation.

On Friday, the Ontario Court of Appeal overturned those convictions in a 2-1 decision that left judges divided over the issue of whether a person can consent in advance to sexual activity that is expected to occur while unconscious.

In a dissenting opinion, Justice Harry LaForme said Parliament, through “no means no” provisions in the Criminal Code and other legislation, has expressed “its clear view” that advance consent to sexual activity under those circumstances is impossible and any consent by J.A.’s spouse “was negated when she was choked into unconsciousness.”

But Justice Janet Simmons, writing for the appeal court majority, said permitting a person to consent in advance to sexual activity expected to occur while unconscious or asleep is entirely consistent with the principles of human dignity and autonomy.

“Where a person consents in advance to sexual activity expected to occur while unconscious and does not change their mind, I fail to see how the Crown can prove lack of consent,” Simmons said, with Justice Russell Juriansz agreeing.

J.A.’s spouse, whose identity is protected by a court order, said she and her partner were into sado-masochistic activity that included bondage and had attempted “erotic asphyxiation” in the past as a means of heightening sexual excitement.

She also said they had discussed the possibility of anal intercourse as a way of “spicing up” their five-year relationship, although what happened that night in May of 2007, when she awoke to find herself on “all fours” and being penetrated with a penis-shaped device, was “quite spontaneous.”

At J.A.’s trial in 2008, the defence reminded the court of former prime minister Pierre Trudeau’s famous declaration that the state has no place in the bedrooms of the nation. The Crown argued that for consent to sexual contact to be legally valid, a person must be consenting at the time the sexual activity occurs. The Crown’s position was accepted by Justice Dianne Nicholas of the Ontario Court of Justice, who said that under the circumstances, the binding of the complainant’s hands and her sodomization by J.A. was “dehumanizing” and degrading.

But in Friday’s decision, Simmons said there is no sense in the Crown’s argument that consent to sexual activity must be given contemporaneously. A competent person, for example, can consent to surgery which is to occur while unconscious and not in a position to withdraw consent once anaesthetized.

As for J.A.’s spouse, she changed her story after she took the witness stand. She originally went to police and gave a videotaped statement complaining he had assaulted her without her consent while she was unconscious.

In court later, she said she had consented to the acts and that she went to police because she was angry with J.A. because she believed he was going to leave her and seek custody of their 2-year-old son.