Get Your Mind Out Of The Gutter

Your mind's dirtier than dirt itself.

When someone has generally dirty thoughts, likely after a Heh. moment just occurred or they saw something that looks wrong. Many commercials like to do this to the viewer by having something that intentionally looks sexual but then turns out to be taken out of context and made the viewer think something dirty. To an extent, this could be thought of as a Fuck You moment as the creators of the ad want their audience to feel ashamed of themselves for thinking of something that was dirty and rong.