Jen shows off fake baby bump.

Check out the photo above of Jennifer Aniston showing off a huge baby bump.

She is pregnant with triplets in a new spoof ad for smartwater (watch the video below).

The 43-year-old actress, who is engaged to Justin Theroux, has been the face of the bottled water brand since 2010.

In the new video clip, former Friends star Jen, wears a fake pregnancy belly as she unwinds.

The tape - said to be security footage filmed inside her LA mansion - also shows her crashing a sports car, and revealing that her famous locks are actually fake as she peruses her collection of wigs.

The viral vid features cameos by funnyman Jimmy Kimmel and American Idol host Ryan Seacrest.

It also reveals Aniston has a swimming pool filled with smartwater.

(Image: Smatwater)