Kendall Jenner was out and about in Vegas this past weekend to enjoy the Super Bowl -- but it looks like one of her exes made it into her suite as well ... and it wasn't Bad Bunny.
Eagle-eyed fans noticed a photo that Michael Rubin's daughter, Kylie, posted on her Insta Story from Sunday ... which shows her sitting next to socialite Will Makris (the dude sleeping in Kim Kardashian's suite) -- and while she was cracking jokes .