Hannah Walters, 32, dressed in men’s clothing and used the name Tarjit Singh while tricking the victims into having sex.
Walters also subjected the women to controlling behaviour, violence, and aggression, leaving them afraid to speak up about their suspicions.
One of the victims was just 16-years-old when she met Walters through Facebook, and told the court she was beaten up when she found the dildo and asked about it.
Their first sexual encounter happened when she was naked and Walters was fully-clothed, with the victim later telling police: “He looked like a guy, he acted like a guy, it’s not an everyday thing, is it?”
Walters lied to the second victim, telling her he had been born male, had a sex change to become a woman as a teenager, and claimed to be now in the process of changing back again.
The third victim met Walters through the Plenty of Fish dating website, believing she was dating a man until she heard Walters’ father “call him ‘Hannah’ and told me he was a girl”.
“I realised everything was a lie, and to have someone you loved do what he has done makes you feel sick”, she told police.
“You feel like you are stupid for believing someone you thought you could trust. I never thought anyone would do that to me, especially someone I cared about.”
The court heard Walters used a sex toy to simulate intercourse with the woman, but then suddenly claimed to have just gone through a sex change operation from male to female.
When they ended up naked in bed together, the victim said she expected to see signs of the operation, including scarring, but could not see anything.
She said a storyline on Hollyoaks about transgender issues had helped her to understand Walters was lying, and ultimately found Walters’ birth certificate in the name Hannah Murray to confirm the truth.
The woman said she discovered Walters had previously been to prison and was held in a women’s jail, undermining the sex change claim.
The woman said she had always previously been in straight relationships, and came forward to protect other women from Walters.
“He is a manipulator, he is crazy”, she added. “He is a spiteful and malicious woman that needs some serious help.”
The defendant, who now identified as transgender male and was referred to in court by the pronoun ‘he’ and as ‘Mr Singh’, claimed to police that all three women consented to the sexual encounters and “had full knowledge of me being a female”.
Mobile phone evidence showed incriminating websites Walters had visited, including FreeToMProsthetics.com, a company making ultra-realistic prosthetic penises.
Melissa Garner, from the CPS, said: “These victims have been deceived, betrayed and lied to in the most disturbing and traumatic of ways. One of the victims was just 16 years old when she met the defendant.
“Tarjit Singh, who was born as Hannah Walters, presented himself as a man, wore men’s clothing and used a man’s name. He tricked three innocent women into believing he was male and when questioned, he violently attacked them and intimidated them into continuing relationships.
“Singh has never admitted his crimes and has continued to claim that these victims were aware of his gender.
“The victims in this case have shown immense courage in coming to court and giving evidence.
“Sexual offences can be some of the most complex cases that we prosecute. I hope these convictions go some way in providing the victims with closure. The CPS is committed to bringing sexual offenders to justice.”
Walters, from Caledonian Road, north London, denied but was convicted of three counts of assault by penetration, six counts of assault occasioning actual bodily harm, and one count of making a threat to kill.
Judge Oscar Del Fabbro remanded Walters into custody until sentencing on July 27.