We all fake it sometimes, but Sarah takes it to a new level.

On the next episode of Brothers & Sisters, the Walkers all plan a surprise birthday celebration for Sarah. The problem is that she's been lying to Luc about her age this entire time.

Awkward! It's hard to keep up with the truth for Kitty too, as she fakes a new persona to appeal to a handsomely rugged handyman. This could be a seriously funny episode.

Here's ABC's promo for Sunday's "Faking It" ...

[video url="http://www.tvfanatic.com/videos/faking-it-promo/" title="Faking It Promo"] [/video]

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.