Reese Witherspoon grabbed Jennifer Aniston's butt on the red carpet at the Oscar Awards last night (22.02.15).

Jennifer Aniston

Jennifer Aniston

The 'Wild' star, 38, couldn't resist having a little squeeze of the 46-year-old actress' pert derriere while she was being interviewed by 'Live at the Red Carpet's Ryan Seacrest at the Dolby Theatre.

The cheeky gesture caught the brunette beauty off-guard, with her squealing, "Oh oh," before realising it was her friend who had pinched her posterior and adding: "Oh, hi, honey."

The pair struck up a bond when Reese played Jennifer's little sister on the US sitcom 'Friends', and the 'Cake' star has admitted she still considers the blonde bombshell to be her younger sibling.

Speaking to 'Entertainment Tonight' prior to the Hollywood ceremony, Jennifer said: "Look at [Reese], she's so cute. So pretty, she's my little sister, even if she's [just] my TV sister."

Meanwhile, Jennifer's impressive performance in 'Cake' may not have earned her an Academy nod this year, but her secret admirer Eddie Redmayne was thrilled on Sunday when his portrayal of Stephen Hawking in 'The Theory of Everything' won him Best Actor.

The 33-year-old hunk, who married his partner Hannah last year, recently admitted he's obsessed with Jennifer and has been stalking her at different showbiz awards.

But it seems Eddie's fondness of the American starlet hasn't creeped her out in the slightest.

She explained: "He can follow me as much as he wants. As long as [my fiancé] Justin [Theroux] is okay with it."