Usher was accused in court papers of "consciously and purposefully" withholding the fact he'd contracted herpes from a celebrity stylist and "continued to have unprotected sex" with another woman.
According to documents obtained by RadarOnline, Usher was diagnosed with the sexually transmitted disease in about 2009 and 2010, roughly when he filed for divorce from Tameka Foster.
However, he allegedly told the unnamed woman he had tested negative for the virus, despite a "greenish discharge" from his penis.
The court documents stated: "Believing Raymond's statements that it had been nothing and cleared up, [she] continued her relationship.
But three weeks later, the victim felt "very sick" and woke up with a "fever of 100 degrees, chills, headache, and aches and pains".
She "also developed lesions and blisters in her vagina" and was diagnosed with herpes.
In the paperwork, she said she "feels that her health and body have been ruined" and "has suffered severe emotional distress and has been extremely depressed knowing there is no cure".
Court documents showed the U Got It Bad hitmaker - who is married to Grace Miguel - paid US$2754.40 (S3721.78) of the woman's medical bills in 2012 and settled the lawsuit on December 28, 2012, for a total of $1.1 million.
Meanwhile, Foster, the mother of the star's sons Usher, 9, and 8-year-old Naviyd - has insisted the case has "nothing" to do with her and she's in "good health".
She wrote on Instagram: "Do not come on my page discussing rumors or adult people that have NOTHING to do with me. I have been divorced 8 years... Some issues are not my business... ex husbands, ex friends, bitch-maids, snakes, hoes, characters, etc.
"Not my circus, not my clowns. I'm good and my health (Everywhere is great), well my right knee hurts and I need reading glasses but otherwise I'm awesome and enjoying the sun. Miss me with other grown folks crazy gossip.. Not my business at all. I'm living my bestest life. Always. Miss me with the bulls**t. Thank you. [sic]"