Justin arrives at Selena's house to take her to Cynthia's party. Selena's family comes in to her room. Her sister Christina asks if Justin is Selena's boyfriend, and she replies that they're "just dating". Janice thinks that Selena is going to a high school dance. Justin tries to correct her, but Selena stops him. Selena's dad Harold tells her not to get into any trouble with the boys. Marina tells her that boys have cooties. Selena goes outside with Justin. Janice yells at them not to drink and drive as they drive away.
At the party, Selena has Justin kiss her to make Cynthia jealous. Cynthia asks Justin what he's doing with a loser like Selena. Justin tells her that he's dating her now, and Selena says that they're happy together. Cynthia says that it's not her problem if he wants to date a loser, and now she's available to date someone better than Justin. She says Justin was a scrub anyway before leaving.
Cynthia goes to get Tyler's attention. She flirts with him, but he isn't interested. He says he isn't a big fan of the music, so Cynthia immediately gets the DJ to change the song. Mackenzie says she is the one who picked the song, and Cynthia replies that it's her fault Tyler hates her. Mackenzie apologizes, but Cynthia kicks her out of the clique. She is immediately replaced with M'kenzyie. Cynthia sees Tyler with his girlfriend Emma and races over, but leaves after getting angry. She takes her anger out on Selena and tackles her, causing her to fly through the air and injure her forehead. Justin runs to help her but is scared off by Cynthia. Tyler runs up to help Selena instead. Selena gets up to fight Cynthia, but Tyler stops her, saying that violence doesn't solve violence. Cynthia stops the party and tells everyone to go home.
Selena wakes up covered in bandages. Tyler tells her that she has a concussion and that he bandaged her up. He offers to call the hospital, but Selena tells him not to, because she would be grounded if her parents found out she went to a party. Emma introduces herself to Selena. Justin drives Selena home. Selena sits in her room and talks about her plan to collect as many boyfriends as possible.
- First appearance of Justin's car