While fighting one of the Highbreed, Ben's parents catch him transforming into Swampfire. They forbid him from using the Omnitrix after having proof of a black eye from the fight, forcing Kevin and Gwen to fight the DNAliens by themselves. After trying to sneak out as Echo Echo, Ben gets grounded and is made to spill the beans about Gwen, getting her grounded, leaving Kevin alone. Kevin's trouble with the DNAliens and the Highbreed eventually pushes Ben over the edge, and he breaks out of his house as Humungousaur in front of his parents to help. After a short battle aboard a small ship carrying a rare isotope which the DNAliens plan on using, Ben's parents come to the rescue, admitting that they are proud of Ben and understand what he needs to do.
Sandra: He's such a good boy. Carl: Ben Tennyson is not a good boy. He's a great boy. I don't know what's bad coming.
Sandra: Do you really think we're that gullible? We were teenagers once too, you know! Carl: I really don't know what to say. Sandra: Well, I do. Benjamin Tennyson, you are grounded! Echo Echo: What? You can't ground me! I'm a super powered alien! Sandra: You're a super-powered alien who's about five minutes from forcing me to reconsider a lifelong disbelief in corporal punishment! Carl: Up the stairs, young man!
(Ben as Echo Echo is sitting on his bed, shaking his legs. Ben's phone rings.) Echo Echo:(answers the phone) Hello? Gwen: Where are you?! We have a situation here! (camera moves to show that Gwen and Kevin are being chased by numerous DNAliens) Kevin: And a lot of DNAliens. Echo Echo: Okay! Aim the phone at them! (Gwen points her phone at the DNAliens. Echo Echo fires a sonic blast through the phone and sends the DNAliens flying. Carl and Sandra enter. Sandra snatches Ben's phone.) Sandra: Who is this?!
Kevin: (looking at Ben) Hey! I thought you were sent your room without supper! Humungousaur: Enjoy me while you can. I'm gonna be grounded for the rest of high school.
Ben: You've got to listen. My friend is in trouble! I've gotta go help him! Sandra: I don't wanna hear another word! You are not leaving this room! You are not calling anyone, you are not IMing anyone, you are not texting anyone, you are not MyFacing anyone! Ben: MyFacing? Carl: You will sit here alone until we tell you otherwise. Understood?
Ben: It's a sacred trust. I cannot divulge that information. Never, never, never!
Gwen: You ratted me out. Ben: I can explain. Gwen: You've gone nose to nose with Vilgax without even blinking. Ben: Vilgax never gave me the mom look!
Ben: You don't understand! This is a matter of life and death! Carl: The only life we're concerned about is yours! You're staying right here! Sandra: Don't look out there! Look at us. Ben: (thinks for a moment and makes up his mind) (Sighs) I'm sorry. I love you guys. You're awesome parents. You raised me by example and time after time, I've seen you put other peoples' needs first. I can't obey you now without disobeying everything you've ever taught me, about life, the world and responsibility. Sandra: Ben, we forbid you to- Ben: So when I get back, punish me however you want but right now, I have a friend who's in trouble! (turns into Humungousaur) Humungousaur!!! (breaks the ceiling and run through the window breaking the whole wall) (turns round realizing what he just did) Sorry. I'll fix that later! (continues running) Sandra: He just walked out on us! What are we gonna do? Carl: We're going to listen to our son.
Kevin: (laughs) Aw, man. Ben: What? Kevin: The Highbreed gave you a black eye. I like him better already.
When Ben is explaining about the Omnitrix to his parents, he says the DNAliens are the ones who are planning to destroy Earth.
When Kevin is facing the Highbreed for the second time, some of the black patterns are missing from the Highbreed's shoulders. Later when Kevin is captured and confronting with the Highbreed before Ben's entrance as Humungousaur, the missing patterns are back in place.
Although it is mentioned in Good Copy, Bad Copy that Ben's left eye twitches when he lies, it does not twitch when he lies to his parents about fighting the Highbreed.