Lisa and Jess Origliasso first hit the spotlight in 2005 with their debut album The Secret Life of... which was led with their hit single 4ever.
Though they're famous for being twins, not everyone is buying it.
According to a crazy fan theory, the sisters don't share the same DNA.
Speaking with Sydney radio hosts Fitzy and Wippa on Wednesday morning, the girls revealed that they've had backlash from fans about their twin status.
"Early on in our careers, it was written on Wikipedia and in the paper the fact that we are twins is a publicity stunt," the girls told the radio hosts. "And the fact that we were born on Christmas Day was a publicity stunt."
Some haters even went as far to say they weren't even related, while another rumour that circulated was that Lisa and Jess were in fact male twins.
But the rumour that offended them most was that the singers were "twinsexual" (involved in an incestuous relationship), which started when they were snapped holding hands.
"We often hold hands when we need comfort," they laughed. "We shared a womb, you cant get more closer than that!"