The High School Musical star and the country music pop star were romantically linked earlier this week after enjoying an intimate dinner together.
However, while Taylor was alone, networking at the 2012 Sundance Film Festival in Park City, Utah, Zac was out partying with Ashley Tisdale.
After a red carpet appearance together to promote their upcoming movie The Lorax, and gushing remarks about each other, the couple were thought to be more than just friends.
But while many people expected Zac to arrive on the arm
Ashley and Efron have also been romantically linked in the past after he was pictured with her during his break-up with ex-girlfriend Vanessa Hudgens.
Ironically though, she is currently dating Taylor Swift's ex boyfriend and Boys Like Girls frontman Martin Johnson.
Taylor made the most of her time at Sundance however and was seen mingling with a host of stars at the iconic festival.
