"It's so cool," Topher Grace told PEOPLE of his former costars' marriage

Credit: Araya Diaz/Getty(2); Inset: Frazer Harrison

Mila Kunis and Ashton Kutcher just got the Eric Foreman seal of approval.

When the longtime couple finally tied the knot, it was a dream come true for That ’70s Show diehards everywhere – including fellow cast mates!

Topher Grace (aka Eric Foreman) couldn’t help but gush about how happy he is for the newlyweds.

“It’s so cool,” he told PEOPLE Tuesday at the American Ultra premiere in L.A. “Imagine two of your great high school friends, who weren’t dating in high school but were buddies and you’re all in the same friend group and they grow up and they fall in love, get married, have a kid.”

The cast has remained close over the years, even working together on other projects and celebrating each others’ birthdays. So it only makes sense that when Kunis and Kutcher got together, everyone was thrilled.

“I’m so happy for them. I really am,” said Grace.

Grace can’t bask in nostalgia for too long, though: He has his own wedding to think about!

The actor, 37, proposed to True Detective actress Ashley Hinshaw, 26, in January after more than a year of dating – but it looks like this groom is taking a back seat when it comes to the wedding planning.

“I have no part in that!” he told PEOPLE. “That is all her. I know to show up, and I know which date.”