Cooper Hefner and Scarlett Byrne

Playboy heir Cooper Hefner popped the question to his girlfriend, actress Scarlett Bryne, in London Tuesday.

The couple had been together for almost two years before Hefner flew oversees to ask Bryne's father for her hand in marriage. When he got the OK, the 23-year-old heir proposed with a massive yellow diamond ring.

Afterwards, the couple reportedly celebrated at the local Ritz hotel.

The young businessman's famous father, Hugh Hefner, tweeted a celebratory message Thursday, writing, "Sending love and congratulations to my son Cooper and his fiancee Scarlett on their engagement!!"

    Sending love and congratulations to my son Cooper and his fiancee Scarlett on their engagement! https://t.co/TGejDbtpdH
    — Hugh Hefner (@hughhefner) August 6, 2015

Bryne, 24, is best known for her roles as Pansy Parkinson in the Harry Potter series and Lexi in Falling Skies. Bryne will also appear as a villian in season 7 of The Vampire Diaries.

After the proposal, the actress shared a cuddly photo of herself and her beau, writing "I was lucky enough to fall in love with my best friend."