Frenemy Mine is the fifteenth episode of Season 7.
When Timmy Turner saves Vicky's life after her attempt to torment him backfires, she is shunned by her fellow evil babysitters, and loses all of her friends. After Timmy suggests to her that she try being friendly, Vicky begins to smother Timmy with friendliness, and he must find a way to change her back to her mean self, since she won't let anyone else near him!
The people of Dimmsdale are throwing a parade consisting of nothing but extremely slow moving construction machinery. Timmy is at the parade with his parents, as well as his godfamily; Cosmo, Wanda, and Poof; who are disguised as balloons. Vicky rides by on a tar truck and sprays Timmy with tar, then covers him with feathers, which making Timmy both weird-looking and funny. But when she hops off the truck to laugh at Timmy, she gets stuck to the tar on the middle of the street and a slow moving steam roller is heading right toward her. Wanda tries to convince Timmy to save her but Timmy hesitates. Wanda then yells at him and Timmy has his godparents turn into a jackhammer and he frees Vicky, who screams in fear at Timmy "Do you know what you've done!?". Then, several robed figures surround Vicky and kidnap her.
Vicky wakes up at the "B.R.A.T." headquarters, which stands for Babysitters Raging Against Twerps, she gets scared because it looked like a tomb and everyone looked like skeletons. B.R.A.T. is a secret society of fellow evil babysitters led by Lauren Ledergerber. But when Lauren's mother flicks on the lights, the dark and scary tomb-like headquarters is revealed to be nothing but a girl's room and the robed figures are really girls who seem to be younger than Vicky. The B.R.A.T. members tell Vicky they witnessed Timmy save her life, which makes their group as a whole look weak, and they take off Vicky's necklace (which looks like a bat). Vicky cries and begs them to give her another chance because they are her only friends, but they still send her down the "Loser Chute". She winds up flying out of a sewer, and pops up from under Timmy who was standing on a manhole, being laughed at by Cosmo for saving Vicky.
Vicky blames Timmy for causing her to lose all of her friends. Timmy shoots back by saying she doesn't have any friends because she needs to be "friendly" before walking away from her. This causes Vicky's heart to grow to normal size and she gives a familiar creepy smile, just like The Grinch from How The Grinch Stole Christmas. Timmy wakes up the next morning to see Vicky still smiling creepily and holding a smiley faced bacon and eggs with the same smile as her. Timmy cannot converse with Cosmo and Wanda for long, because Vicky snatches him away and takes him to do girly stuff. She begins to treat Timmy more protectively, and becomes extremely hostile to anyone else that gets near Timmy such as Chester and A.J.. Vicky gives him a full makeover (a shirt, pants, and haircut that is all identical to Vicky's) and begins to harass him non-stop on the phone.
Driven to the edge because of Vicky harassing him so much, Timmy starts to take action. He decides to make her hate him again so she would go back to "normal". When she shows up with her prized autographed Chip Skylark poster, he pulls out his chainsaw and tears it apart.
Timmy then hits her face with a pie, but Vicky manages to control her anger even as her face begins to turn redder with rage. Timmy sends her to get lemons for lemonade and hands her a beehive, which causes all the bees to sting her and swell, but that still isn't enough to make her angry at him. While plotting his next move with Wanda, Timmy suddenly remembers that it was at the slow-moving machinery parade where he saved Vicky, thus this gives him an idea to return to where it all started. Timmy takes her back to the scene of the crime, the slow moving machinery parade.
The parade is still going on since the beginning of the episode, at least several days have passed and Timmy's parents have been there this entire time, now sporting long white beards and an elderly appearance. While Vicky sadly watches her former friends, the B.R.A.T.S., tormenting some younger kids, Timmy tars her with the tar truck, and then he dumps garbage from the garbage truck on her. Timmy then hops in a nearby construction vehicle and hits her with a wrecking ball. Vicky's heart shrinks and then turns glowing and evil looking again. In a fit of rage, returns to the favor to Timmy by tarring him, covering him with garbage, hitting with a pie, and other things she held in when Timmy did those things to her. The B.R.A.T.'s see this and welcome back Vicky into their society, which Vicky takes over and forces the other babysitters to act as her horses. Timmy talks with Cosmo, Wanda, and Poof, happy that everything is back to normal. That is, until they hear screaming nearby, and see that Vicky and her friends are stuck in the tar and are about to be flattened by a steamroller. Instead of saving Vicky this time, Timmy decides to sit back on a lounge chair and watch until the steamroller flattens Vicky and the babysitters.