Patti LaBelle is up to her old tricks: screaming at people. Last night at a concert in Vancouver, an audience member the diva had presumably invited to come dance onstage began unbuttoning his shirt. That wasn’t part of the deal Miss Patti had in her head, so she interrupted him and the music (“Lady Marmalade,” of course). “Don’t you dare, not on my stage!” she hollered. She explained with what initially seemed like good humor, “I am not Nicki Minaj or that little, uh, Miley.” The dancer took this as an opportunity to arch his back and present his ass to her. Here’s a tip: Do not arch your back and present your ass to Patti LaBelle.