Mila Kunis and Ashton Kutcher's relationship 'fascinating' to former colleague

A former colleague has said he finds Mila Kunis and Ashton Kutcher's relationship 'fascinating'. Photo / Getty

A former That 70s Show actor has revealed watching Ashton Kutcher and Mila Kunis' on set was "fascinating".

Topher Grace admits he was surprised when close friends and former co-stars, who tied the knot earlier this year, first started dating in early 2012.

Former That 70s Show actor Topher Grace was surprised when fellow show buddies Mila Kunis and Ashton Kutcher got together. Photo / Getty

However he but thinks it's "so great" they fell in love after working on the show together for eights years.

When Watch What Happens: Live host Andy Cohen asked if there were ever signs the couple were meant to be together on the set, the 37-year-old actor was vague.

"It's funny, 'cause it's fascinating to everyone but it's fascinating to people in the cast, too. Because, no. I mean, we were all buddies, but...It's so great.

"It's like two of your best friends from high school, like, met years after high school and got together. It's so cool."

Kunis, 32, and Kutcher,37, played high school sweethearts on the comedy.

The brunette beauty, who landed the role of Jackie Burkhart when she was just 13, previously admitted her now-husband was her: "first real kiss."

"My first real kiss ever was with him on the show. And when That '70s Show had a prom, my date for the prom turned out to be my fiancé.

"We can honestly say that we went to prom together! Although I do think that in that episode I went home with someone else. We don't talk about that part."

- Bang! Showbiz