Who's Kim Kardashian's Man This Week: Kanye West or John Mayer?

Is birthday girl Kim juggling two guys? She's been hanging out with both John Mayer and Kanye West, but are they more than just friends?

Kim Kardashian is turning 30 today (for real). And although she claimed her dating life was "nonexistent" last weekend in Vegas, E! News has learned that's not entirely true.

This week, she's been linked to both Kanye West and John Mayer. So what's the real deal?

She did indeed hang out with Kanye yet again this week in Chicago, attending a screening of his film Runaway at the Icon.

"Kim stopped in for 15 minutes and said hi," a source close to the reality star tells us. "They're just friends."

But the two also had a friendly dinner after the screening at Bijan's Bistro, according to In Touch.

And Kim's managed to make another new pal while shooting in NYC.

As unlikely as this pairing sounds, an insider says that she has been out with John Mayer a few times recently. (Oh, and we're not even gonna get into all the boy drama she's facing on Sunday's season finale of Keeping Up With the Kardashians.)

In other Kim news, she's celebrating yet again tonight during a private bash thrown by Scott Disick in the Big Apple. And on Saturday, she'll be hosting another soiree at Glo nightclub in Long Island, where she'll receive a million dollar cake.

The club tells E! that a jeweler is making Kimmy a custom, diamond-encrusted cake that's worth more than one million.

"It wasn't her idea," they tell me of the lavish treat. But not so fast. Kim herself is now saying she doesn't want the costly cake.

"First of all, this is the first I've heard about this, and I would never allow anyone to spend that much money on a cake. Making a million dollar birthday cake is just ridiculous! I'd rather they give me a cupcake and donate the rest of the money to the homeless!" she posted on her blog.

"This something we're doing as a gift for her," a club rep tells E! News.

The cake, which was designed to break the world record for the most expensive cake, will be unveilved tomorrow to the press in NYC.  

"If she wants it, great. If not, that's okay, too," the rep said. Diamonds are great, but who wants two-day old cake anyway?