Heidi Montag: Coming On to Justin Bieber, Moving in With Former Hugh Hefner Plaything

We were astonished to read it, but Heidi Montag is apparently serious about divorcing Spencer Pratt - and she's already playing the field again ... sort of.

For the first time since the separation rumors started, she took to her Twitter and openly said she's getting divorced, then promptly hit on Justin Bieber.

She may rue the day once his fans get wind of it.

The Hills star wrote: "@justinbieber now that I am getting divorced I think you and I should do a photo shoot together! Cutie ;) ! I'm closer to your age."

Closer than what is not clear. She's 23 and he's 16. That is minimum security prison territory for the 'Tag. Still, who can resist that bowl cut? Yummy ...

MMM: That ice cream isn't the only thing Heidi finds delicious.

In addition to salivating over the Bieb online, Heidi also Tweeted some interesting information pertaining to her upcoming new reality show with Jen Bunney.

Apparently, she and the former Hills co-star will be welcoming a third roommate to their Malibu girls' pad (allegedly owned by Spencer's pal Cougar Zank):

Former Hugh Hefner girlfriend Karissa Shannon!

Yes, one of the Shannon Twins, but apparently not the other. We have no idea why, how she knows Heidi, or whether anyone would watch this crap, but:

"@karissashannon will be moving in my Malibu house this summer and will be filming our new show!" wrote Montag to her 1,063,188 followers today.

Whatever. That's all. Here's Heidi's Justin Bieber Tweet, which she'll probably take down after 'tween girls send her death threats a la kim Kardashian:

NOTE: Follow THG on Twitter and get all the Justin Bieber news without the creepy come-ons. Seriously, Heidi. He doesn't pass the half-your-age-plus-seven test.