As she gets older, she’s just getting worse! The socialite’s birthday was just this past Sunday, and she was showing us a side of her …that we already knew! Hilton was at the opening of Peek Nightclub inside Harrah’s Casino Lake Tahoe on Saturday night and looked like a nut job on stage! I mean, I know most people usually like to turn up on their birthday, but she did the exact opposite as she was down on the ground – stumbling on stage. Her 21-year-old (Yes, 21-years-old.. only) boyfriend, River Viiperi, held on to her like a gentleman as she was dancing provocatively. Just when you thought things were bad enough, after all the partying, her man ended up in the hospital on Sunday due to a bad skiing accident. Paris explained on her Twitter, posting: “Just got out of the hospital with @RiverViiperi. He was doing a high jump while skiing & the ski sliced in to his leg! 19 stitches! Oww! (sic)” SMH! See the photos of her acting up at the casino in the gallery!