Sideshow: Sir Paul on approach to 70

Paul McCartney turns 70 in June, yet the Beatle rocks on.

He says he has already beaten the odds. "You really don't want to go beyond 50," a former manager once told him. "It's going to get embarrassing." So recounts Sir Paul in the March issue of Rolling Stone, a mag founded by kids who thought it was all over at 30.

"I'm never going to believe I'm 70, I don't care what you say," Paul says. "There's a little cell in my brain that's never going to believe that." The singer, who plans to continue recording and touring, says it's simple: "If you're enjoying it, why do something else? And what would you do?" Can Paul see himself jamming onstage at 80? "I can imagine it . . . rocking on until a grand old age. . . . The only thing would be when it's not pleasant anymore," he says.

"But it's way too pleasant at the moment. And it pays. Good gig, man. But I know exactly where you're coming from, though. How long can this go on?"

Lindsay Lohan, who last month was hit with a tax lien of $93,701.57 for failing to pay her 2009 federal taxes, has been bitten again by the jaws of the IRS. E! News reports that the IRS has filed a second lien against LiLo, for failing to pay 2010 taxes.

Already in a hole for the $93 grand, LiLo now owes an additional $140,203.30.

"Lohan's business manager," Lindsay rep Steve Honig tells E! News, "is working out an acceptable arrangement with the IRS."

Sienna Miller engaged to Sturridge?

Sienna Miller's baby bump has been noted on various Fashion Week red carpets in New York. But the Factory Girl star won't confirm - or deny - that she's engaged to the baby's papa, the sweetly intense Brit thesp Tom Sturridge (Pirate Radio). Sienna did give away one tantalizing clue: She has been sporting a diamond-and-platinum engagement ring.

Jennifer Aniston: 'I'm not knocked up'

"I'm not having triplets. Not having twins. Nor am I having one baby," Jennifer Aniston tells GQ mag in response to rumors she is carrying beau Justin Theroux's babies. Adds Jen: "I did not elope. . . . You heard it here. I'm not knocked up." Jen, who turned 43 on Saturday, says the public seems fixated on the idea of her becoming a mom. (Makes sense, she was so maternal on Friends.) "I still kind of go with, if it happens, it happens. I'm calm and peaceful with whatever the plan is." Jen costars with Paul Rudd in Wanderlust, opening Feb. 24.

Justin Theroux: 'I am happy'