Ashton Kutcher is annoyed that Laura Prepon didn't tell him about her engagement.

Ashton Kutcher

Ashton Kutcher

The actor's 'That 70s Show' co-star Laura recently got engaged to his pal Ben Foster but Ashton says he only heard about it on the news.

During Ashton's stint as a guest-host on 'Live! with Kelly', Laura appeared on the show and the actor said: "She just announced this engagement, and I had to find out in the news! And she's my friend! And it's not just a random engagement. It's an engagement to another friend of mine! So I'm double upset that neither of them told me! I got off the plane in New York like, 'What?'"

And Ashton, 38, who is married to his and Laura's '70s Show' co-star Mila Kunis, added: "When Mila and I got engaged, she was like, 'What? This is crazy! You guys, it was like 20 years ago. You were friends and no one saw this coming, and now you're engaged and I have to find out this way'. They were friends 20 years ago! They're all my friends, and everybody's hooking up, and it's weird!"

Laura, 36 and Ben, 35, surprised everyone when she debuted her engagement ring at the 'Girl on the Train' premiere in New York earlier this week.

The pair only went public with their relationship in July.

A source said: "She was holding onto Ben and was all over him. They were really close, talking and laughing [at the premiere]."

Ben and 'House of Cards' star Robin Wright called time on their engagement last year after three years of dating.