But they're loud, and the owner of the house comes into the room and finds them. It's Krabs' mother. Krabs (or as mother dearest calls him, Eugene) turns to his comrades to ask why they didn't tell him it was her house. To which the terrifying response is "Why didn't you ask?"
There are many layers here, each worse than the last. When they're breaking in, Patrick states that they're "panty professionals," which SpongeBob complements with "We score here all the time." To recap, Krabs has been talked by his friends into stealing his own mother's frilly panties (an action which you really don't need anyone to tell you is 100% sexual), and he now has the knowledge that these same friends routinely steal his mother's panties, and think it's perfectly fine for people to steal their own mother's panties.
This is the kind of thing that would make Sigmund Freud point at the screen with a trembling finger, his mouth frozen in a silent scream, blood streaming from his ears. A movie would include a scene like this only as a serial killer's origin story.