"I reached out to him when he had the baby, which is so awesome," Rumer said of Ashton, who was married to her mum Demi Moore for eight years until their split in 2013. "I saw photos of her (baby Wyatt). She's very cute…"
CLICK ON PHOTOS FOR GALLERY
Rumer Willis 'reached out' to Ashton Kutcher after the arrival of his baby daughter
She then added, "I realised the other day, he was a year younger than me when he and my mum started going out. It would be like me meeting someone who already had three teenage kinds, kind of going into that situation was crazy."
Rumer also spoke about the start of Ashton's relationship with Demi, and how he came to join their "crazy clan".
"They were just hanging out… my mum has always made how (my sisters and I) feel about situations the most important thing. I think it was more her going, 'Hey, this is my life and these are my kids and my priorities. So if you want to come and kind of join our crazy clan, this is what I already have kind of built.' Which I find so amazing and respectful.
Rumer Willis also spoke about how Ashton Kutcher came to join their 'crazy clan'
"It's one of the things that I admire most about my parents, is that they set such an incredible example for kind of putting their children first and keeping a family together, no matter what."
Rumer is Demi's eldest daughter with Bruce Willis. The Hollywood superstars were married from 1987 until 1998, and are also parents to Scout, 23, and Tallulah, 20.
Bruce has been married to model Emma Heming-Willis since 2009, and the couple are themselves now parents to two little girls, two-year-old Mabel, and six-month-old Evelyn.
Bruce Willis has two young daughters with wife Emma Heming-Willis
"He's shifted into this goofy, fun kind of demeanour," Rumer said of her dad. "He has two little babies now, which is crazy to me! They're so awesome and so fun."