Since they already have a two-year-old daughter together, Mario Lopez knew he had to find an extra-special engagement ring for his girlfriend of four years, Courtney Mazza.

PHOTOS: Stars' giant engagement rings

As detailed in the new issue of Us Weekly (on stands Friday), the Extra host, 38, proposed to Mazza, 28, with a gorgeous, 5-carat diamond engagement ring over New Year's weekend in Ixtapa, Mexico.

PHOTOS: Celebs who got engaged in 2011

"The platinum setting is swarming with round brilliant-cut diamonds all the way from under the finger to the collar of diamonds that encircles the center stone," jewelry expert Michael O'Connor tells Us in a description of the future Mrs. Lopez's new bling. "Mario clearly knows that platinum will hold all of the diamonds securely forever, including the impressive brilliant-cut center diamond. The estimated price tag: $80,000!"

PHOTOS: 90s TV stars - then and now

The couple, who have been together since 2008 and are parents to 2-year-old Gia, plan to wed in Mexico later this year.

Get more Us! Follow us on Twitter, Friend us on Facebook, Subscribe to Us Weekly