Season 7 Episode 1 "Demons": Stabler goes undercover as a sex offender.

Season 7 Episode 8 (or 9) "Starved": Olivia goes undercover in a dating service to catch a rapist.

Season 8 Episodes 1-6: Olivia goes undercover as Persephone with a suspected eco-terrorism group. She is only shown in episode 1 and episode 6, when she first joins the group and when the case leads her back to SVU.

As of now, I don't know of any where they both go undercover. If you find out please let me know the episode!

I remember those...I don't know if they're actually undercover, but they're at this bar, and Elliot's in a suit with glasses, and he kinda flirts with Liv who's all dressed up at the other end of the bar....

Sounds like it would be the dating service one with Liv.

Nope, I saw that one and Elliot wasn't in it...or that part of it at least...

You're right. If you find it, please post so I can watch it!!!

Finally found it...its in the episode Risk. I think that's in season 3...I don't know how to post it though so someone else will have to do that...

Thanks! I'll find it.

Risk is not in season 3 (i know cause i own it) trying to help

its risk season 4

In the episode "Undercover" Fin and Olivia go undercover at Sealveiw correctional center where they are investigating crooked guards.