Kirsten�'s father, Caleb, arrives to celebrate his birthday party. He brings his new, young, attractive girlfriend, Gabrielle. After Caleb criticizes Kirsten�'s judgment, party and family business, Sandy tries to encourage his wife to leave the real estate business run by her father. Next door, Julie tells Jimmy that she is filing for divorce and, at the party, Caleb turns his pleas for a job down, but seems interested in his soon-to-be ex-wife.
Marissa continues to feel unsure about her feelings for Luke and Ryan. But after she walks in on Ryan kissing Gabrielle, she goes home and sleeps with Luke for the first time. Back at the birthday bash, Seth and Summer share their first kiss.
"The Girlfriend" File: