As Kourtney and her boyfriend Scott get ready to celebrate their two-year anniversary, she starts to re-evaluate their relationship. They've dealt with trust issues in the past, and Kourtney starts to worry that Scott's recent behavior could mean he's cheating on her. Determined to find out the truth, Kourtney follows him and is shocked to see him hug another girl. Will she end up calling it quits with Scott for good? Meanwhile, Khloe has a biopsy for skin cancer when her dermatologist becomes concerned about a mole on her foot. When Khloe goes MIA for a few days, her family starts to fear the worst.