外側溝

外 = 夕 + 卜 : There's a hole in the wall of the airplane's bathroom (ai4), and from outside (外), a bat (夕) wants to enter. Willy Walrus (w) is very afraid of bats, so he does his best to hinder the bat from entering with a voodoo staff (卜).

侧 = 亻 + 则 : Wu Zetian (则) and the King of Chu (c) got married in the elevator's bathroom (e4) and after the ceremony they are so drunk that they have to lean against (侧) Rosa Luxemburg (亻) to not fall down.

沟 = 勾 + 氵 : In front of the outhouse (ou1) Guy Fawkes (g) drew (勾) a photo-realistic comic (勾) of an open gully (沟) on the floor. The people are afraid to step onto it because it looks so real. They only start to believe Guy Fawkes that it's not as he spills a bottle of water (氵) over his chalk painting.