For those Twihard Robert Pattinson fans you'll already know that Rob's a smoker, there have been plenty of photos showing him enjoying a ciggie.

But Rob thinks his secret has just come out and is worried about what his mum will think. Aww Hollywood superstar, Robert Pattinson is scared of his mum. We love it!

A source told the Sun: "Robert tried to make sure his security shielded him from lurking photographers. But a snap has appeared in America.

"Robert's since admitted he's been scared about his mum finding out."

We hope his mum does find out and gives Rob a wrap over the knuckles for having such a disgusting habit...

Rob at the Remember Me premiere....