A transgender woman has been found guilty of sexually assaulting a male partner by failing to disclose her gender status to him, meaning he could not consent to the sexual activity, British prosecutors said on Friday.

Ciara Watkin, 21, performed sex acts on the man, also 21, who she had met on social media site Snapchat in June 2022, but did not disclose her transgender status to him.

The Crown Prosecution Service said Watkin had told the man that she was on her period and meaning he could not touch her below the waist.

A few days later the pair met again, after which Watkin blocked all contact with the man until she eventually got back in touch and told him during an exchange of text messages that she was transgender and had male genitalia, the CPS said.

“It is clear from the evidence in this case that, prior to engaging in sexual activity with the victim, Watkin had made no attempt to inform him of her transgender status,” said Senior Crown Prosecutor Sarah Nelson.

“The victim has made clear in police interview that he would not have engaged in sexual activity had he known that Watkin was transgender and, consequently, these events have had a significant impact on his mental wellbeing.”

Watkin, from Stockton-on-Tees in northeast England, had admitted lying but her lawyers told her trial that it would have been “blindingly obvious” to the man that she was not biologically female, the BBC said.

She was convicted of two charges of sexual assault and one charge of assault by penetration following a trial at Teesside Crown Court and will be sentenced on October 10.