Rihanna may be on top with a sold out world tour, but her sponsored lipstick brand reportedly gave a fan herpes at a May 7 concert, souring the sponsorship and the singer's cache.

Starkeema Greenidge, 28, is seeking damages for the "mental anguish and emotional distress" caused the "We Found Love" singer's RiRi Woo lipstick, which Greenidge sampled with the help of an employee for Rihanna's sponsor, MAC.

"[She] didn't use a fresh or new lipstick tube, but rather one that had been used for other patrons," claimed the lawsuit. While reusing tubes is practiced in the U.S., tubes are typically sanitized first.

According to The Daily Beast, when Greenidge allegedly asked if the lipstick tube was clean, the MAC employee quickly said yes.

"This is going to happen over and over again if nothing is done," said Greenidge to the New York Daily News.

Rihanna's "multi-collection" deal with MAC Cosmetics launched in February, with the initial shipment already sold out, reported The Guardian.

The 25-year-old's other sponsorship deals include a men's perfume, Rogue, to be released in September, coconut water brand Vita Coco, and Armani.

Unfortunately, RiRi Woo's latest lipstick hitch may hurt the relationship between the sponsor and the Barbadian singer.

"Consumer safety is a top priority at MAC Costmetics, and we take these matters very seriously," a spokesperson for MAC stated.

"We are closely reviewing these claims."

Check out a review of Rihanna's Riri Woo below: