Kieran Culkin reveals how he felt working with his ex Emma Stone on A Real Pain

Kieran Culkin enjoyed getting to work with his ex Emma Stone on 'A Real Pain'.

The 41-year-old actor dated 'Cruella' star Emma, 35, from 2010 until 2011 but were reunited on the set of the upcoming comedy-drama - in which she serves as a producer - and felt confident going to work on the first day because he knew that he would know at least one person there.

He told E! News: "She's great. She's a really wonderful person. It's nice because you go into a job and most of the time you don't really know anybody. But in this case, going in, I'm like, ‘Oh, OK, well at least that part's taken care of. I'm going into a situation where the producers are going to be great. And where the filmmaker will be nice, too. It was good."

Earlier this month, the 'Succession' star admitted it had become "funny" to even refer to Emma - whom he met when they starred together in 'Paper Man' - as his ex-girlfriend because he sees her solely as a friend these days as he recalled being more aware that the 'La La Land' actress was headed for stardom than she was.

He told Rolling Stone: "It's funny to even say 'ex. To me, she’s just a really good friend of mine and my wife’s. She’s lovely and great.

"I met her when the rocket took off. I was right at the beginning of the huge launch; I got to watch all that firsthand. And I remember at the time that I was a little more aware of the direction she was going than she was.

"She would be like, 'Oh my god! I just got this opportunity…'And I’d be like, 'Yeah, but of course you did! Everyone loves you and you’re great.'

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