Jimmy Kimmel roasted Robert Downey Jr's manhood and past drug use in his bombshell opening monologue at the 2024 Oscars on Sunday - while also appearing to upset actress Emma Stone. 

The host, 56, returning for the fourth time, left the A-listers grinning and cringing in equal measure as he took to the stage.

Downey Jr. 58, who won Best Supporting Actor for Oppenheimer was stony-faced as Kimmel made a crass joke at the start of the ceremony - referring to the reformed coke addict's past addictions.

He said: 'And Robert Downey Jr., one of the highest points of his career. But Robert has been' - as RDJ pointed at his face, leading Kimmel to add: 'Was that too on the nose or a drug motion you made?

'But look at him, he's so handsome, so talented, he's won every award there is to win. Is that an acceptance speech in your pocket or do you just have a very rectangular penis?'

The joke fell flat as RDJ looked somber while staring at the camera while fans slammed Kimmel for his 'bottom of the barrel' jokes about substance abuse.

Later, Kimmel appeared to catch the ire of Emma Stone as he lampooned her performance in Poor Things, joking about the explicit sex scenes by saying: 'Those were all the parts of Poor Things that we're allowed to show on TV.'

The camera then cut to Stone making a less than impressed face, with some speculating she even called him a 'p***k.'