Before quitting “American Idol,” handsome Mario Vazquez feared another contestant was going to expose his “secret” personal life, The ENQUIRER has learned exclusively.

But by leaving in such a public manner and then dodging questions, Mario sent the rumor mill into overdrive — leading many Web sites to question his sexuality.

And the New York Daily News even published an account of his “close attachment” to a male hairstylist.

Mario, 27, stunned his fellow finalists by telling them on March 12 that he was leaving.

Then in a press interview, he denied there was “anyone special” in his life.

But The ENQUIRER learned that by making that statement he upset not only his New York City boyfriend — identified by several sources as a hairstylist — but also triggered the resentment of the stylist’s friends.

Mario’s quitting also triggered neighbors and friends in the Bronx neighborhood where he was raised to tell The ENQUIRER it’s an open secret that Mario is gay.

“Everybody wants to know why Mario quit ‘American Idol.’ It’s because a rival contestant threatened to go public with details about a relationship Mario desperately wanted to keep private,” a pal told The ENQUIRER.

“But Mario’s former boyfriend is devastated that Mario is denying there is anyone special in his life. This could be the last straw for their relationship.”

Another source, who knows Mario’s love interest, told The ENQUIRER that their relationship was well-known at the Manhattan hair salon where the stylist presently works and which is the same company where Mario was once employed.

When The ENQUIRER caught up with the stylist, he didn’t deny a relationship with Mario, saying only: “I’m sorry, no comment.”

But he earlier told an insider: “I’ve had enough of Puerto Rican men — and of one in particular.”

The ENQUIRER also learned that Mario was a regular at The Web — a Manhattan club which features male gogo dancers and is frequented by drag queens and gay Asian men.

When asked for comment, Mario’s publicist told The ENQUIRER: “I smell rumor, innuendo and falsehood.”

There was speculation when Mario quit “American Idol” that he had left the show to pursue a recording contract with a different label. The “American Idol” producers said at the time that Mario’s contract prohibited him from signing any other deal for at least three months after the current TV season ends. But within days of leaving, he hired the lawyer that helped former “Idol” Clay Aiken out of his contract with the show’s management company.

Neighbor Shirley Seth, who says she’s known Mario for 23 years, told The ENQUIRER he kept his sexual orientation a secret from his mother.

“He never told her he was gay, but it didn’t come as a surprise to me. I never saw him with a girlfriend.”