The couple met while starring on 'That 70s Show' 15 years ago and recently started dating and Kurtwood Smith would love for them to tie the knot and invite all of their former co-stars from the TV show.
He told E! News: ''It's amazing. They're both great people, so I'm happy for them.
''Maybe they should get married. We'll all go to the wedding and that could be the reunion. It'll be a reality show.''
Even though they played an on-screen couple on the comedy series, Kurtwood insisted there was no off-screen romance because Mila, 29, was too young for Ashton, 34, when they previously worked together.
He said: ''Of course they played boyfriend and girlfriend, but they had completely separate lives.
''You have to remember Mila was a kid. That was awkward for Ashton at the beginning. He was like 19 and she was like 14 or 15.''
Ashton recently opted to mix business with pleasure by taking his girlfriend along on a work related trip to Australia.
The 'Two And A Half Men' actor hosted a star-studded dinner in Sydney, Australia on Thursday evening (01.11.12) - with guests including Brian McFadden, Mel B and model Ruby Rose - to promote his successful business investment Airbnb.
Before that the happy couple enjoyed a trip to Japan where onlookers said they were happily flaunting their love.