Hollywood star Zac Efron refuses to divulge intimate details of his relationship with Vanessa Hudgens, over fears he’ll look foolish if they split up before his gushing words are published.

The High School Musical heartthrob insists he’s deeply in love, but concedes relationships are wildly unpredictable - and he’s determined not to look stupid should their romance end.

He says, "I don’t want to be another 20-year-old actor talking about my relationship. I want to keep that private - sorry. All I can say is that Vanessa’s a great girl. And I’d hate to say more about it because by the time this interview comes out, it may or may or may not be relevant."