While it was never confirmed that Efron was unfaithful to Hudgens, The Thing notes that his sky-rocketing career, which constantly required him to be away, ultimately caused the relationship to end.
After HSM, the 34-year-old star went on to make several successful movies in 2010-2011, including Charlie St. Cloud, New Year’s Eve, and Robot Chicken: Star Wars III. Meanwhile, Hudgens' Beastly and Sucker Punch did not perform so well, with the media outlet intimating that their different career paths may have caused a wedge between them.
Opening up about the relationship on The Hollywood Reporter's Awards Chatter podcast in 2019, Hudgens spoke fondly about how the romance first started while also revealing that tensions between them were starting to cause problems at work.
“I remember one time we did have a fight, and it was while we were at rehearsals, and I remember [HSM director] Kenny Ortega coming around the corner with the most concerned look on his face like, ‘Oh no, is our movie going to fall apart right now?'” she said.
Although things between the couple had largely seemed stable from the outside, reports of Efron's wild partying as well as his drug and drinking problems cast a new light on the relationship. According to People, the actor had serious substance abuse issues in 2010, with one source recounting an incident where Efron and his friends went to a strip club as soon as Hudgens left for a New York photoshoot.