Overview
"Hooked" is the 16th episode of the fifth season of the CBS sitcom How I Met Your Mother and 104th episode overall. It originally aired on March 1, 2010.
Plot
Future Ted mentions how most his stories have been romantic or have portrayed him in a fairly positive light, but in this next story, he was simply a jerk. Ted tells the gang that he has invited a woman over under the pretense of checking out his antique camera collection, which Barney classifies as "bait". He's tried many types of bait (slot machine, trampoline), but found that a teacup pig is the best kind, which Ted then borrows after seeing the reaction Robin, Marshall and Lily gave.
Later, Ted is at MacLaren's telling the gang about this woman, Tiffany (Carrie Underwood), he snared using the pig. She says she's really into him, but can't be with him "right now" because of her boyfriend. The gang sees through her ruse, telling Ted that he's been "hooked", a euphemism for stringing someone along until they meet someone better.
Everyone gives an example: Marshall did a high school classmate's homework and was her "secret boyfriend", Robin allows her pre-morning show cameraman to pamper her, and Lily's high school flame, Scooter (David Burtka), works at her school as cafeteria staff, where she doesn't exactly tell him that a romantic relationship is impossible.
From Wikipedia (CC BY-SA 4.0).