get (one's) mind out of the gutter

slang To stop having and giving voice to lewd, inappropriate thoughts (about someone or something). A: "Heh, that painting totally looks like two people doing it!" B: "Why is it always about sex with you? Grow up and get your mind out of the gutter for a change!" A: "And then she compared my model rocket to a phallus." B: "Ew, gross. I wish she would get her mind out of the gutter." Enough with the dirty jokes, OK? Get your mind out the gutter.