 When Sandy forgets his and Kirsten s 20th wedding anniversary, he finds himself going to a lot of trouble to make it up to her. Meanwhile, Seth and Ryan s respective relationships with Alex and Lindsay add to the trouble, and doubt falls upon their futures together. First with Seth over spending time with her, while Ryan talks with Lindsey about where they stand during after school study sessions. Marissa and Julie continue to butt heads over D.J. during a photo layout shoot for their house, which leads Julie to offer money to D.J. to stop seeing Marissa. Also, Summer wants to take her relationship with Zach to the next level and she meets his mother, Elaine, and his sister, Abby, for the first time in which the superficial Summer finds herself a fish out of the water with their broad-minded personalities.