But, as you might expect, the lyrics are more complex than appearances suggest. Kendrick starts off with the familiar rap trope of bragging about his sexual prowess (the walls of the title are the walls of a vagina - eugh). Things turn darker in the second verse, where Kendrick reveals his partner's husband is in prison - literally behind walls. In the third section, the rapper talks about the walls of his inner conscience, and how his actions haunt him. Sadly, a fourth verse about dry wall construction was deleted for length.
The video illustrates the thought-provoking storyline in a rather vulgar fashion - at one point Kendrick's sexy dancing is so vigorous he bursts through the walls of his neighbour's house, with hilarious results.
Watch below. Or, better still, listen to the album.