The probability that season 21 of CBS' Amazing Race will have a gay winner is set at 50 percent.

That's because two of the four final teams include gay members.

After the elimination of 7 teams, one team will emerge victorious in Sunday's 2-hour season finale.

Engaged couple Josh Kilmer-Purcell and Brent Ridge star in their own reality series, The Fabulous Beekman Boys. After two seasons on cabler Planet Green, the series moved to the Cooking Channel.

The couple worked together to narrowly escape elimination and make it to the final four.

β€œI guess the two of us is better than each one separate,” Kilmer-Purcell said in a post challenge interview.

Team Chippendales includes best friend Jaymes Vaughn and James Davis. Vaughn, who is gay, recruited Davis to enter the competition and said he plans to give the $1 million prize to his father, who is fighting cancer.

β€œAt this point it's an incurable cancer, and we're trying to do everything we can to help him turn it into a curable cancer,” he told People magazine.

While the reality show has often included teams with gay members, a gay couple has not won the race since 2003. Reichen Lehmkuhl and Chip Arndt won the 4th season of Amazing Race. They remain the first and, so far, only gay couple to win the competition. Lehmkuhl went on to appear on cabler Logo's reality series The A-List: New York.

(A trailer for the finale is embedded on this page. Visit our video library for more videos.)