Ben 10 Omniverse S4 Ep 5 - Gender & AP Transformations

Season 4 Episode 5 Mud Is Thicker Than Water
Gwen walks up to Max but is surprised to see her cousin, Lucy, instead. A flashback happens wherein 11-year-old Gwen is talking to Max, who is about to tell her something. However, she is surprised to see Lucy disguised as him and Lucy says she is staying at her house for a couple of months and promises to Gwen that she won't get mud on anything. Ben notices Jerry passing by and Magister Patelliday walks up to Gwen saying that janitorial services are complaining about the mess she left behind in the girls' restroom. Gwen gets upset by this, but it turns out that Lucy disguised herself as Patelliday. Ben quickly leaves while Gwen runs into Kevin and asks why he is there. However, it's just Lucy again and another flashback happens where a younger Lucy is asking Gwen about what Kevin is like. Ben appears beside Gwen, but Gwen suspects it's Lucy. However, Ben explains himself and Gwen says it's Ben, but Lucy reveals herself greatly annoying Gwen.