Gillian Anderson show off her expanding bump at the premiere for “The X-Files: I Want to Believe”.

The mom-to-be recently told US Magazine that “The only thing I do when I’m pregnant is eat and sit on my butt!”

“I’m not really craving anything, but there’s the lazy part of me that thinks, ‘What’s the point in working out until I have the baby?’ Then we’ll actually do something!” she said.

“I know that’s not necessarily the right way to look at it,” she added, “but that’s just me.”

Anderson told Us besides having “a couple of films coming out later in the year that I’ll do some promotion for,” she plans on focusing her life on mommy hood.

She and beau Mark Griffiths are already parents to son Oscar, 20 months.

She also has a daughter Piper, 13, from a prior marriage.