Charlie Sheen

Charlie Gets Engaged!

By Michelle Tauber

UPDATED 07/23/2007 at 01:00 AM EDT • Originally published 07/23/2007 at 01:00 AM EDT

When the time came for Charlie Sheen to choose an engagement ring for girlfriend Brooke Mueller, the actor knew exactly what he wanted. "He told me that he wanted to get a flawless diamond," says Beverly Hills jeweler Lord Alon Barak, who custom designed the platinum-set, 11-carat yellow diamond ring valued at $500,000. But what the Two and a Half Men star didn't expect was his own reaction upon seeing the finished product. "He was very, very emotional," says Barak. "You saw him melt away. He was overwhelmed."

So, too, was his bride-to-be, who accepted Sheen's surf-side proposal during a Costa Rican getaway last month. The engagement caps a low-key romance that began when Sheen, 41, and real estate investor Mueller, 29, were introduced by actress and mutual pal Rebecca Gayheart at a party in April 2006. Says Barak, a longtime Sheen pal: "They're very lovey-dovey. You see them holding hands like glue."

Even more significantly, Mueller has been bonding with the most important girls in Sheen's life: Sam, 3, and Lola, 2, his daughters with ex-wife Denise Richards, 36. (Their marriage legally ended last November.) Earlier this month, Mueller joined Richards and Sam for a girls' lunch in Beverly Hills. "Brooke loves his kids very much," says Barak. While the pair have yet to set a wedding date, the engagement ring—complete with a raised "C" and "B" under the diamond—serves as a happy prelude. "When she takes the ring off, there's an imprint, kind of like a tattoo, on her finger," says Barak. "It's nice to see that she complements him and he complements her."