Ducking out the side door of the famous Las Palmas Nightclub is High School Musical legend Zac Efron ... who is abruptly asked if she is gay.

Rumors have circulated Hollywood for some time that Zac is gay and wishes to come out of the closet about it, but is allegedly pressured by his PR peeps to keep it on the down low until he's older.

Whatever the case may be ... 'tis unfortunate that we just can't collectively transcend limited paradigms that seek to restrict our inherent, cosmic freedoms -- just sayin'.