Even Adele gets stage fright in front of her favorite celebrities! In a new interview, published on Thursday, December 7, the singer, 35, revealed one of the guests she was petrified to perform in front of during her Las Vegas residency: Lady Gaga. “And I’ve spent a bit of time with her, but I rate her so hard. I was like, ‘The show’s terrible. It’s rubbish. I’m singing terribly. I’m not funny. My dress is rubbish this week.’ I was judging myself. And she’s not like that. But she made me really, really nervous,” the Grammy winner said, adding that she almost “shat myself the whole show.” “The …