While in 2007 they feted their 21st birthdays at an intimate dinner at the Chateau Marmont, this year Mary-Kate and Ashley Olsen opted for a far more public celebration — the duo partied with more than 100,000 people at the Bonnaroo Music Festival in Tennessee over the weekend. The twins, who turned 22 on Friday, reportedly arrived in Manchester on Thursday, and were subsequently spotted downing diet Red Bull and Patron at a local bar. They spent Friday evening playing dinner host to 11 friends (and one surprise guest, Josh Groban) at the Hermitage Hotel, before heading out to the My Morning Jacket show at midnight. Their rock'n'roll weekend continued on Saturday, when Mary-Kate and Ashley rubbed elbows with Bonnaroo revelers at the Jack Johnson and Pearl Jam shows. By Sunday morning, the duo was ready to head home — but not before making a quick Starbucks stop on their way out, of course.

On Wednesday night, while most people were dressed up like cats or vampires or fairies, Ashley Olsen was trying on her own costume - the much-much-younger-woman getup. She was spotted in the lap of Olympic bicyclist Lance Armstrong, according to a New York Post source:

The 21-year-old twin showed up to the Rose Bar at the Gramercy Park Hotel Monday night with Tory Burch's ex, Lance Armstrong, 36. Our bar spy said, "They came together with a group of friends. Ashley drank red wine, sat on his lap and they were making out all night. They left together around 2 a.m."

Revelation: No wonder things fell apart between Lance and his most recent ex, Tory Burch - she's 41! No wonder Lance and Sheryl Crow called off their engagement! Lance isn't ready to be married and have kids - he wants to date them!

Another odd couple seen out and about this week: Owen Wilson and Jessica Simpson. The two were spotted at the Huntley Hotel in Santa Monica Sunday night, acting so romantical that onlookers told Life & Style, "It was definitely a date. They were doing their best to avoid being photographed." Before heading back to Owen's Malibu home, the date was already getting steamy, according to another source: "He couldn't keep his hands off her," a witness tells the mag. The two Texans allegedly hit it off earlier this month while visiting Austin to appear in a video with Willie Nelson, and have since been spotted together on two separate occasions.

Revelation: No wonder Nick Lachey's and Jessica's marriage fell apart! He wasn't tortured! Since divorcing the jock in 2005, all of Jessica's male interests have been the total opposite of Nick. Adam Levine, John Mayer, and now Owen Wilson - all three men with that sort of "tortured artist" edge that a co-dependent southern gal could fall for. Then again, my personal opinion is that Jessica and Owen's publicists put them up to this to get both their careers back up and running. Regardless, I'm sure Owen doesn't mind having to spend time with his new "drug"!

Finally, the real shocker: Madonna and Tupac almost had a baby together, according to Lucy O'Brien's new book "Madonna: Like an Icon." The NY Daily News reports:

O'Brien says Madonna, in her mid-30s, "desperately wanted children and had various relationships with unlikely men." The singer's friend Alison Clarkson recalls when she was briefly dating Tupac Shakur, one year before his death.

"She was going out with him ... but homegirls were saying to him, 'I can't believe you're going out with a white girl,'" - so she got dumped!

This isn't necessarily new information though. In 2004, Blender.com's list of the "33 Things You Should Know about Tupac Shakur," dedicated #27 to Tupac's "special" relationship with Madonna:

"He and Madonna were friends. maybe more than friends..."

In his tell-all biography, Got Your Back, Tupac's former bodyguard Frank Alexander suggests the two slept together: "We were watching a talk show, and they flashed a picture of [Madonna's ex-boyfriend] Carlos Leon and Madonna walking into a New York building on the screen. 'Pac said, 'You know, that used to be me.'"

Revelation: That's all Tupac's bodyguard knows? I thought guys liked to brag about these things?

"Unlikely Couples" is certainly the phrase of the week!