Ok, so the original cut of this film was supposed to have a love triangle in it, and apparently Shane kissed Greg, or something. I've never seen the film, but was the character of Shane supposed to be gay?
If I was a Disney Kid, I'd want to be known as the Disney Kid that said NO to singing.
In the uncut original film, Shane has a sexual relationship with both Greg & Anita. He falls in love with both of them. If you recall, they are all roommates when Shane moves out of his dad's house in NJ.
A brief scene of Shane having sex with Anita (in the Studio rest room) was included in the DVD release---this wasn't in the theatrical showing. The gay scenes were cut from both.
I don't believe the writer/director ever intended to concretely define Shane's sexuality. You could view Shane as basically straight--dabbling in same-sex activity only fueled by drugs and money/career advancement or actually bisexual. I think it's supposed to be up to the viewer to interpret.