John Gray probably made some enemies due to the way he acted on last week's premiere of Top Design, but during the second episode of Bravo's new reality competition series, the 40-year-old offers an explanation for his unruly behavior: he's taking medication to treat HIV.

"I just want everyone to know I'm HIV-positive," Gray tells his fellow contestants during Top Design's Wednesday, February 7 episode.  "I'm not making excuses or apologies."

Gray, a gay Chicago resident who was diagnosed as HIV-positive in 1993, said the anger he displayed during the Top Design premiere was caused by testosterone he takes to counteract lower levels of the hormone in his body induced by HIV.  Prior to the show's start, Gray's testosterone dosage was upped 400% because he wasn't sure how long he'd be away from home.

"After the first episode, I asked myself why I was so angry, and it was a light-bulb moment," Gray told USA Today in a report published in Tuesday's edition.

The self-taught designer is believed to be only the second reality television contestant to reveal he is HIV-positive.  The first was the late Pedro Zamora, an AIDS educator that appeared on MTV's The Real World: San Francisco in 1994.  While Zamora's disclosure made his Real World housemates apprehensive, USA Today reported Gray's comments "barely cause a reality show ripple among the group" of Top Design cast members, all of whom share a dorm-style hotel for 10 weeks.

"Everyone was shocked by John's behavior the first few days, " Carisa Perez-Fuentes, a 26-year-old Top Design contestant from Highland Park, NJ, told USA Today.  "[After his disclosure] there was some heightened understanding of his behavior.  Relationships changed for the better.  And he mellowed out."

Top Design executive producer Clay Newbill also happened to serve as a producer during Zambora's The Real World season, so he was able to put Gray's revelation into perspective.  "Times have changed," he told USA Today.  "Back then, society's understanding was different.  We saw it as an opportunity to educate people."  Gray told Top Design producers of his condition during casting, however they said there were no plans to disclose it to the cast or viewing audience. 

"This isn't a relationship show, so it wasn't an issue," Newbill told USA Today.

While a television audience may currently have a better understanding of Gray's condition then when it was presented by Zambora more than 11 years ago, advocacy groups are still applauding Gray's decision to be forthright.  "This visibility is important in raising awareness that HIV is a major health issue," Damon Romine of the Gay & Lesbian Alliance Against Defamation told USA Today.

But Gray said he's not looking to raise society's level of awareness about his condition. 

"I don't want to be the new face of HIV or be on the cover of Out," he told USA Today.  "I felt the cast was entitled to an explanation for my behavior."

Top Design airs on Wednesdays at 10PM ET/PT on Bravo.