A woman is suing Xavien Howard ... alleging the Miami Dolphins star gave her an "incurable STD."
The woman, ID'ed as "Jane Doe" in the suit, claims she met the football player back in 2018 ... and shortly afterward, began dating him. She says at the time, Howard told her he had no STDs -- and even provided her with a copy of his negative test results.
In 2019, however, she said in the suit that Howard discovered he had contracted genital herpes ... but never informed her of the diagnosis, and continued to have unprotected sex with her.
According to the docs, obtained by TMZ Sports, Doe says she eventually contracted the STD from Howard ... and ultimately confronted the 29-year-old over it.
She claims the cornerback -- a three-time Pro Bowler who signed a five-year, $90 million contract extension with Miami this year -- initially denied knowledge of his condition, but then came clean.
"Maaaaan I been told you I was sorry for giving it to you," she says Howard told her. "But what can I do now? The damage is done. You keep bringing it up as if it gon change sumthin. Like yo a** can't move on."
Doe is suing for negligent transmission of genital herpes and intentional infliction of emotional distress. She's asking for unspecified damages.