In 2014, when he was first accused of sexual assault and hitting women, Jian Ghomeshi said he liked "rough sex" and BDSM, calling his sex life a "mild form" of 50 Shades of Grey.

This week, the former TV and radio host is in court facing allegations from three women, amounting to four criminal counts of sexual assault and one count of overcoming resistance to sexual assault by choking.

The case is one of the country's most highly publicized sex assault trials ever, and — thanks to the Ghomeshi's own Facebook posts — has already wandered into the grey legal zone around BDSM and consent. But it also underlines a rarely used, and very serious, criminal charge that could see Ghomeshi put away for life.

"You kicked my ass last night and that makes me want to fuck your brains out tonight."

The choking charge, which comes from the same section of the law that prohibits date rape, could land Ghomeshi with a life sentence in prison if he's convicted. That's because, according to the prosecution, he allegedly wanted to do something worse than only sexually assault one of the women who took the stand on Thursday: He prevented her from resisting it.

But prosecutors must prove he had the intent to commit sexual assault for the charge to stick. And if Ghomeshi intends to argue that the choking, and other rough sexual acts, were consensual — as he's suggested in the past — it might raise the question of whether consent is even possible, and whether the choking was so severe that it inflicted serious bodily harm.

It's alleged that in 2003, Ghomeshi choked and slapped Trailer Park Boys actress Lucy DeCoutere. On the stand, DeCoutere described it as "a power thing."

In a Facebook post written in 2014, Ghomeshi said, "I have always been interested in a variety of activities in the bedroom but I only participate in sexual practices that are mutually agreed upon, consensual, and exciting for both partners."

After the alleged assault, DeCoutere wrote in an email, "You kicked my ass last night and that makes me want to fuck your brains out tonight."

"You've got to have a way of withdrawing consent."

On Thursday, the actress testified that she didn't consent when he choked and hit her.

If Ghomeshi's position in the ongoing trial is that the choking happened, but it was consensual, it could raise a question that hasn't been raised in Canada's courts for 20 years, and one that plagues courts all around the world: when does BDSM become sexual assault?

In a 1995 case relating to BDSM, the Ontario Court of Appeal made a precedent-setting decision in R. v. Welch, that you can't consent to serious injury during rough sex. The issue hasn't been explicitly addressed in a Canadian BDSM-related case since then.

"Theoretically, police could prosecute for BDSM activity if it caused bodily harm, like candling or burning or cutting or whipping," University of Manitoba law professor Karen Busby told VICE in 2014. But, she noted, "You've got to have a way of withdrawing consent."

In other cases that involved BDSM, though, lower courts have "more or less ignored Welch since it was decided in 1995," though it remains the binding precedent in Ontario, Busby, who specializes in the law around consent, said.

"I was not able to consent to the choking or the slapping because I was just receiving it. So, no, I didn't consent to it."

In one case, charges were laid for strangulation even though the supposed victim told police she was a willing participant in erotic asphyxiation. The problem arose when she passed out, which the judge decided meant she couldn't consent.

In another case in which the accused was convicted of second-degree murder, the court said the cause of death, manual strangulation, was something a reasonable person would expect to create risk of bodily harm.

But it's hard to say whether those cases could have any impact on the Ghomeshi case, Busby said.

When it comes to consenting to choking, it depends what precedent you follow, she said. Asphyxiating your partner by choking them until they can't breathe can lead to bodily harm, Busby explained. And according to the precedent set by the appeal court in 1995, you can't consent to that.

If Ghomeshi agrees the choking happened, but says it was consensual, it's possible the court might ask the question of whether it was severe enough for DeCoutere to be able to consent in the first place.

In that Facebook post Ghomeshi wrote in 2014, he said he engaged in "rough sex" and BDSM but that it was consensual. But DeCoutere said on the stand Thursday of the alleged choking and slapping, "It's impossible to consent to something that you're not asked, so no, I didn't consent to it."

"If I was a betting woman, right now I'd be betting the defense is that nothing happened. He didn't hit her."

DeCoutere testified Thursday that she went to Ghomeshi's house after an awkward dinner date in July, 2003. He gave her a tour of his home. After the tour, he started kissing her, which she consented to. Then she said he took her by the throat, cutting off her breath, and slapped her three times. The amount of force he used to choke her was enough that she couldn't breathe, she said.

"He hit me a couple of times and he was looking at me, and then he hit me again, and then he stopped," she said describing how he allegedly slapped her. The slaps were not enough to leave a mark, she testified.

"I was not able to consent to the choking or the slapping because I was just receiving it," she said. "So, no, I didn't consent to it."

Ghomeshi's lawyer, Marie Henein, was able to show during cross-examination that DeCoutere was not certain of the order in which she was slapped and choked when speaking to media about the events. She also raised the fact that the two continued communicating and spending time together after the alleged assault. "I had wanted to turn him into a friend after he had indeed assaulted me," she said.

The defense hasn't yet presented Ghomeshi's side of the story, and he may not take the stand at all.

Busby's best guess was that Ghomeshi's defense will be that none of the assaults ever happened. "I suspect, if I was a betting woman, right now I'd be betting the defense is that nothing happened. He didn't hit her."