Self-proclaimed bisexual MTV star Tila Tequila may actually be stick-straight.

Tequila, who stars in "A Shot at Love With Tila Tequila," a show about her search for the perfect mate, male or female, is not bisexual and it's "all a sham," a source close to the show told the New York Post's Page Six gossip column.

"Tila has and has had a boyfriend for over a year, and she's not really bi. She's made out with some girls in her past, as all girls have, but she is not bi at all," the source said.

Click here for the Page Six report

The insider claims that MTV works hard to pretend she's single and available because she refuses to break up with her boyfriend, "who's like five years older than her. This is a massive scam ... That's why they are not continuing with the show [for a second season], because she won't dump him."

Tequila has also been acting like "a diva" and become a "nightmare to work with," said the source.

"She arrives late and doesn't talk to any of the contestants between takes. She complains she has too much going on."

A rep for Tequila told Page Six, "I'll confirm that she's bisexual and she's a delight to work with."