Two women and a man are suing Usher for failing to tell them he had herpes before sleeping with them.

The lawsuit is set to be filed by celebrity lawyer Lisa Bloom today in California.

At a Monday morning press conference in New York City, Bloom had one of the alleged victims, 21-year-old Quantasia Sharpton, speak about the nerve-wracking moment she learned about Usher's alleged diagnosis - three years after sleeping with the singer.

Quantasia said she has always loved Usher's 'artistry and music,' so her friends took her to a concert of his to celebrate her 19th birthday a few years ago.

Quantasia Sharpton, 21 (pictured), is suing Usher for reportedly having sex with her and not telling her he had herpes

Sharpton (right) spoke at a press conference in New York City on Monday about the lawsuit, along with her attorney Lisa Bloom (left)

Sharpton says Usher slept with her on her 19th birthday a few years ago and failed to tell her he had herpes

She says she was selected from the crowd to go backstage before the show and meet Usher - real name Usher Raymond - because of the birthday crown she was wearing.

Later, she says a security guard came up to her and asked for her number because Usher was 'interested in her'.

After the show, she says she got a call from a blocked number and it was Usher, asking her what hotel she was staying in and the room number. About an hour later, Sharpton says Usher arrived at her hotel and they had 'sexual contact'. But after he left, she 'never heard from him again'.

The latest lawsuit comes after another woman sued Usher (pictured in July 2015) last month for allegedly giving her the disease

Sharpton said she was shocked last month to learn that Usher possibly has herpes, an incurable sexually-transmitted disease.

On July 19, documents were leaked online, showing that in 2012, Usher admitted in court documents to having herpes. Because he settled that case, it was never reported at the time.

But once the documents were made public last month, a woman who said she slept with Usher in April filed a $20million lawsuit against him for giving her the disease.

When Sharpton read about that case, she contacted Lisa Bloom to see what her legal options were, even though she tested negative for the virus when she had a child last year.

While Sharpton doesn't have the disease, at least one of the three clients that Bloom is representing say they caught the disease, and blame Usher for it. One of her clients is a man who said he had oral sex with the star with no warning about his STD

Sharpton says if she had known that Usher had herpes, she 'would have never consented' to sex with him.

She said she 'would not have taken the risk' because her 'health is very' important to her, especially since becoming a mother.

'I feel like my rights were violated, ' Sharpton said.

She said she decided to join the lawsuit against Usher so he 'does not do this to anyone else'.

'You need to warn your sex partners...so they can make their own decisions,' she said.

After Sharpton recounted her side of the story, Bloom took to the podium to explain that the new lawsuit wasn't about herpes. She says herpes is a medical condition and nothing to be ashamed about.

However, as a highly-contagious disease that can cause high-risk pregnancies, miscarriages, and expensive treatment - Bloom says that usher should have told his sexual partners about his diagnosis.

She says he violated his sex partners' rights 'by failing to warn them prior to having sexual contact'.

'At least one of my clients has tested positive - and alleges that it was Mr Raymond who transmitted it,' she said.

She says her clients have been 'anxious and upset; after learning Usher possibly has the disease, and yet he has not 'reached out to any of them directly or indirectly' to either confirm his diagnosis or assuage their fears by saying he doesn't have the disease.

They can't call him either because he always called them from a blocked number, she says.

Their 'trust and faith has been shattered,' she said.

'No one in America - even a popular celebrity - is above the law,' Bloom said, adding that ordinary people like her clients have the 'legal right to be respected'.

Bloom says that her clients are not asking for a specific amount, and they will be fine with whatever a jury decides to award, if they win the case.

It's 'really not about money,' she said.

The Love in This Club singer celebrates his two-year wedding anniversary to wife Grace Miguel in September.