Episode 251: You Have to Wet Yourself into the 12th (S15E4 Internal Affairs)

With the Unit and Liv in some serious transitional waters, IAB Lieutenant Ed Tucker comes in and muddies those waters up something fierce as he draws Liv's new roommate/boyfriend Brian Cassidy into an undercover sting for the Rat Squad to earn him a gold star and re-entry to the hallowed halls of the proper NYPD. Of course, this being the Warren Leight years, Benson and her relationship are put through the ringer, as the 12th Precinct is as dirty as it gets and Cassidy gets caught up in some pretty dicey stuff with a scuzzy cop and his sad and desperate partner. There's plenty of fun to be had, as Cassidy has too many T-shirts, can't dodge a sordid sexual situation with Liv listening to the whole thing, and nearly gets killed before having his special lady friend tell him to shut his yap while cuddling.