Celebrity Applegate Shows Off Engagement Ring By Enid Portuguez Published on April 27, 2010 @ 02:38PM Pin Share Tweet Email Photo: Kevin Mazur/WireImage; Bauer-Griffin Christina Applegate flashed her gorgeous vintage-style diamond engagement ring while out in L.A. yesterday—and it is quite the stunner! Musician Martyn Lenoble (pictured) proposed on Valentine's Day, but the TV star has only recently sported the sparkler, which according to StyleList.com, boasts approximately four carats of diamonds and cost about $70,000. Congratulations to the happy couple!