PEOPLEMila Kunis and Ashton Kutcher through the yearsHOLLYWOOD, CA - MAY 03: Actors Mila Kunis (L) and Ashton Kutcher at the Zoe Saldana Walk Of Fame Star Ceremony on May 3, 2018 in Hollywood, California. (Photo by Alberto E. Rodriguez/Getty Images for Disney) ORG XMIT: 775160226 ORIG FILE ID: 954342780Alberto E. Rodriguez, Getty Images For DisneyMOUNTAIN VIEW, CA - DECEMBER 03: Actors Ashton Kutcher (L) and Mila Kunis attend the 2018 Breakthrough Prize at NASA Ames Research Center on December 3, 2017 in Mountain View, California. (Photo by Kimberly White/Getty Images) ORG XMIT: 775086218 ORIG FILE ID: 885005988Kimberly White, Getty ImagesBUDAPEST, HUNGARY - AUGUST 10: (EXCLUSIVE COVERAGE) Ashton Kutcher and Mila Kunis watch Wiz Khalifa's set during Day 2 of Sziget Festival 2017 on August 10, 2017 in Budapest, Hungary. (Photo by Joseph Okpako/WireImage) ORG XMIT: 775020875 ORIG FILE ID: 829485544Joseph Okpako, WireImageepa05593219 US actors Mila Kunis (L) and Ashton Kutcher (R) take selfies prior to the beginning of the MLB National League Championship Series game four between the Los Angeles Dodgers and the Chicago Cubs at at Dodger Stadium in Los Angeles, California, USA, 19 October 2016. EPA/PAUL BUCK ORG XMIT: MAN31PAUL BUCK, EPAOAKLAND, CA - JUNE 05: (L-R) Actors Ashton Kutcher and Mila Kunis attend Game 2 of the 2016 NBA Finals between the Golden State Warriors and the Cleveland Cavaliers at ORACLE Arena on June 5, 2016 in Oakland, California. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Thearon W. Henderson/Getty Images) ORG XMIT: 643779211 ORIG FILE ID: 538309460Thearon W. Henderson, Getty ImagesXFrazer Harrison, Getty ImagesHopefully, Papa Kutcher won't wear his Stagecoach cowboy getup in the official family photo.Kevin Winter, Getty ImagesCongratulations Mila and Ashton on your engagement! Here's a look back at the lovebirds from 'That '70s Show' to now. Here, they cuddle during a basketball game on Sept. 22, 2013.Justin K. Aller, Getty ImagesMila Kunis tugs at Ashton Kutcher's hat before the Los Angeles Lakers' NBA basketball game on Jan. 3, 2014.Mark J. Terrill, APSelfie alert! The two document a moment at an NBA game in Los Angeles on Jan. 3.Kirby Lee, USA TODAYThe pair show a little PDA before an NFL football game on Sept. 22, 2013.Don Wright, APKutcher and Kunis during the Fox Television Critics Association Press Tour on Jan. 16, 2004.APKutcher, left, Danny Masterson and Kunis perform during the Church of Scientology's 11th annual Christmas Stories fundraiser on Dec. 6, 2003.Getty ImagesOn 'That '70s Show,' which premiered in 1998, Kutcher played Michael Kelso and Kunis had the role of Jackie Burkhart.FOXTopher Grace, left, Laura Prepon, Kutcher, Masterson, Kunis and Wilmer Valderrama get ready for high-school graduation on 'That '70s Show.'Fox Broadcasting'That '70s Show' cast, clockwise from top: Topher Grace, Wilmer Valderrama, Lisa Robin Kelly, Kutcher, Kunis, Danny Masterson and Laura Prepon.FOXThe gang shows off their bell bottoms in a promotional photo for 'That '70s Show.'FoxIn this scene from the TV show's 'Velvet Rope' episode in 1999, Jackie persuades Kelso to go glam.FoxIn 1998, clockwise from top: Valderrama, Masterson, Prepon, Grace, Kunis and Kutcher in a promotional still for Fox's 'That '70s Show.'Fox