Scientists are divided on the issue of homosexuality in twins. Some scientists believe that there's a genetic code that determines whether some sets of identical and fraternal twins will be gay, while others believe that that DNA is not a factor at all. Many twins, however, identify as gay, lesbian, bisexual, and queer.
Who is the most famous set of gay twins? Tegan Quin and her sister, Sara, are both openly gay. Their band, Tegan and Sara, has released seven studio albums. Their latest album, "Heartbreak," debuted at number three on the Billboard charts. They also collaborated with Coolhaus to create an ice cream sandwich flavor called, "Til Death Do Us Part" in favor of same-sex marriage.