DreamsMaster: By “pop” do you mean soda pop, like coca cola? A bathroom in a dream often represents a need to release unpleasant feelings. In your dream the bathroom is covered with pop, something sweetened. Putting it together, this dream could be a metaphor for “sugar-coating your feelings”. If it were my dream, the takeaway message could be that I need to take a more honest look at my feelings about something going on in my life – sugar-coating them will only make an already unpleasant situation even stickier.
On a more literal level… it’s possible in the back of your mind you’ve been noticing mildew collecting, and the dream is a warning that it will take over unless you take action soon!