Mila Kunis and Ashton Kutcher on April 15
04/17/2012 at 08:15 AM EDT
and Mila Kunis
may have been seen out and about together last weekend, but the two are nothing more than friends, a source close to the former That '70s Show
costars tells PEOPLE – and which Kunis's rep confirms.
Kutcher, 34, and Kunis, 28, who played an on-again, off-again couple on the popular sitcom, had dinner with fellow cast members Wilmer Valderrama and Laura Prepon before the group went back to Kutcher's new house in Los Angeles
A source also tells PEOPLE that the mini-reunion won't be the That '70s Show
cast's only get-together this month. The group will make an appearance on Fox's 25th Anniversary special, which airs Sunday.
Kutcher and Kunis were also spotted furniture shopping earlier in the day, reports X17online.com
, but a rep for Kunis dismissed rumors that the two are dating.
"They have been friends for years and met up for dinner with a group of friends," her rep tells PEOPLE.