An Ottawa man accused of being a serial rapist denies he drugged two women and sexually assaulted one of them, instead testifying the sex was consensual and the two women willingly consumed drugs while partying with him.

Philip Wilson, 33, has pleaded not guilty to 45 charges including sexual assault, administering a noxious drug, procurement, aggravated assault and drug trafficking.

The Crown argues there were 14 victims between 2014 and 2015, with Wilson surreptitiously drugging most of them — either with GHB, known as the "date rape drug", or the anaesthetic, ketamine — leaving them unconscious and with no memory that he sexually assaulted them.

None of the women can be identified due to a publication ban on their names.

Accused is defence's only witness

Wilson's lawyer Trevor Brown opened his case Thursday, saying his client will be the only witness defence counsel will call.

Wilson admits he was employed in the drug trade and said he was addicted to drugs as well, Brown said. The women consented to taking drugs, but Brown added "he never provided any of these women with drugs for the purposes of incapacitating them or for the purposes of enabling or assisting him in committing a sexual assault."

Wilson believes the women consented to having sex with him, Brown said. But the defence lawyer conceded sexually explicit videos made by Wilson and found on his phone showed "he overstepped the boundary of consensual activity" and that "he was caught up in the party lifestyle of drugs and that dramatically clouded his judgement."

In a number of cases it was the police who approached the women to show them sexually explicit photographs and videos that Wilson allegedly took of them and often shared with friends.

Drug habit led to dealing

Wilson, wearing a black suit, testified in the judge-only trial before Superior Court Justice Charles Hackland that he started using drugs including marijuana, cocaine, MDMA or ecstasy and GHB recreationally on the weekends. But his habit increased and his consumption bumped up to four days a week.

Philip Wilson, 33, is on trial for 45 charges, including sexual assault, and administering a noxious drug to what the Crown Attorney describes as 14 female victims. "There could be other drugs but I just can't remember," he said.

He told the court that several years ago, he and his live-in girlfriend — who he claimed had an addiction to cocaine — decided he should start selling drugs to support their drug habits.

One night in March 2015, Wilson said a female friend texted him asking if she could buy some cocaine.

He said he had a "prior sexual encounter" with her. When they met up in the ByWard Market, Wilson said it was clear her intentions were to have sex with him.

"She said suggestively, 'Let's go back to my place,'" he said.

Accused claims sex was consensual

He stopped off at his home to pick up some cocaine and GHB, and once inside her nearby apartment they each had a drink and that's when he asked her if she wanted to try some GHB, Wilson testified.

"I told her it was similar to ecstasy, it gives you euphoria and it kind of relaxes you," Wilson told court. "It makes you feel a bit more drunk."

Once she agreed to try it, Wilson said he gave her only about one-fifth of the small vial of liquid GHB, and that he consumed the rest. He also chopped up lines of cocaine, which they both took.

Wilson said "things starting heating up" and claims the women instigated things by first giving him oral sex and then having sexual intercourse with him several times.

He told the court that after the sex was finished with one woman, he went to the bathroom only to return to the bedroom to find she was snoring. He didn't want to leave her apartment without saying anything to her so he opted to send her a text with a heart and flower emoji, he said.

Brown asked Wilson if he intended to give the woman GHB to "knock her out and remove her capacity to make decisions."

"No, we were using it recreationally and it can sexually arouse you as well," Wilson responded.

Woman reported incident as sexual assault

When the woman testified earlier in the trial, she told the Crown she texted Wilson to ask if he wanted to come to her apartment and have something to eat. She denied her invitation had anything to do with having sex with him.

Wilson put his arm around her as they walked to her home and at one point he put something that was glass and cold to her lips and poured some liquid into her mouth, she testified.

The woman went to police the next day to report she suspected she'd been sexually assaulted and that Wilson had put a vial of "unknown" liquid in her mouth.

A vial was recovered in her apartment and returned positive for the drug GHB, while another test confirmed Wilson's DNA was found in her vagina.

Denies taking off woman's clothes

Wilson was then asked about another night in June 2014 when he met up with another woman. She was a friend who bought marijuana and cocaine from him, he testified, and she had a few drinks before they went back to his apartment.

That night he gave some cocaine to the woman and mixed her a drink, but he denied mixing GHB in with the alcohol he gave her.

After she had "a couple of lines of cocaine," he said the woman told him she was "overheating" and not feeling well, and that she went to the bathroom.

Brown then told his client that the woman testified Wilson and his girlfriend had taken off her clothes and were rubbing ice on her.

"No, I remember hearing that but no, I didn't do that," said Wilson.

Brown peppered him with questions: Did he have sex with the woman? Did he give her any drugs other than cocaine? Did her give her ketamine?

Wilson calmly answered "no" to all of them.

Woman called ambulance from bathroom

Wilson told court the woman was in the bathroom for a long time and that he thought she had stomach flu because she complained about diarrhea.

The Crown said the woman told court she realized she'd been given a different drug other than cocaine, panicked and called an ambulance from his bathroom.

Wilson testified he had no memory of the woman calling an ambulance. She left on her own after spending a lot of time in the bathroom, he said.

Brown read a text message the woman sent Wilson a few days later, which read, "You fed me those drugs and I almost died if I hadn't gone to the hospital — WTF don't talk to me ever again."

Wilson texted her back, saying, "I'm not sure what you're talking about but I'll respect your wishes."

Wilson is scheduled to continue his testimony Friday.