The full text is from the lines of a comedy TV drama:
Because fathers never really know who their daughters are. They don't want to know, do they?
It would be terrifying to know who they are and what they do, and because they don't really know any of this, sometimes they can just walk in unexpectedly,and, suddenly, it's like, "Hey, you're a whore. Who knew?"
My question is, does "walk in" here just mean "enter someplace" like enter his daughter's room and says something...?