Mila Kunis and Ashton Kutcher still "feel very young".

The former 'That '70s Show' star - who have Wyatt, nine, and Dimitri, seven, together - will celebrate their 10th wedding anniversary next summer and the 41-year-old actress credited their shared sense of humour and outlook on life for the "spark" between them.

She told E! News: "I still feel like we're very young and we feel very young. I think that's where the spark is.

"[And also] we laugh at everything."

Despite being close to a marital milestone, the 'Goodrich' actress doesn't believe it is a particularly big achievement.

She said: "It's only 10 years. It's not really that long. I look at my parents, and they've been together for 50. That's long."

Meanwhile, Ashton recently reflected on how he parents his two children differently because he is more protective of his little girl.

Speaking on the 'Throwbacks' podcast, he said: “I don’t know if it equates to being a girl dad or it equates to her being my first, but when I had my daughter, I had never been so in love in my entire life.

“And Mila and I talked about it a lot. Like, I’ve never loved anyone this much. Ever.”

Discussing how he parents his kids "differently", he added: “My son, I’m always like, ‘Yeah, let’s go for it.’ Like, yesterday we’re popping wheelies on a bicycle in the driveway or it’s like, ‘See if you can jump down four stairs.'

“[With] my daughter I just want to protect her. When my son cries, I’m like, ‘All right, what did we learn? Let’s move on.’ But when my daughter cries, my heart is out of my body and I can’t put it back in.”

The 'Vengeance' actor noted the "toxic masculinity" he's experienced through his life has allowed him to treat his son differently, but admitted Mila also adopts different approaches with their two kids.

He said: "I also notice the same thing with my wife, like, she’s very strict on our daughter and, like, a gushball with our son.

"I think we balance each other in that way.”