Mayor Bloomberg and girlfriend Diana Taylor appeared at Us Weekly’s 25 Most Stylish New Yorkers party last night. Bloomberg, an honoree, took the stage and cracked jokes in his usual adorably nebbishy fashion. He suggested a feature called “Mayors, They’re Just Like Us!” and advised the audience to “wear what you want, just don’t wear red socks to a Yankees game.” (Get it? RED SOX!) He said he’d learned a lot about being fashion forward, and as a result owns “business suits in 57 shades of gray.” It was admittedly a little corny, but his jokes fell surprisingly flat on the audience of tipsy twentysomething Us Weekly readers. They chatted through his speech, searched for waitresses carrying shots, and rolled their eyes. At one point, he even said, “Hey, it’s hard to write this stuff!” We wondered what was going on — usually Hizzoner is a home run at goofy events. But as we looked around at all of the blank stares in the crowd, we realized what must have been the problem: Nobody had any idea who he was.