Maria Menounos got engaged live on radio today (09.03.16).

Maria Menounos

Maria Menounos

The 37-year-old presenter was stunned when Kevin Undergaro - who she has been dating for almost 19 years - popped the question while she was promoting her new book, 'The EveryGirl's Guide to Cooking', on Howard Stern's SiriusXM show.

The DJ had initially been asking about the couple's relationship before inviting Kevin into the studio and asking why he had never proposed.

Maria said: "Howard, I'm the one who's telling him now, 'We have to do this.' He's like, 'No! I want a big affair. Kris Jenner says she's going to be the godmother and throw the big party.'"

In response, the DJ handed over the microphone as he said: "I think Keven should marry you."

Kevin said: "It was so emotional to hear you say everything, because listening to everything you said there, back when were in the green room talking about what you've been through, I've been through, too...when we wanted to be together, we couldn't because people didn't want us together. And then it was literally like the last 17 or 18 years of us fighting together, and me defending her as best I could...It reminds me just how much I do love you, and although I said that this isn't a proposal, I want to ask you something.

"Would you make me the happiest man on earth and would you marry me?"

Maria was initially in disbelief, but Kevin - who got down on one knee to propose - insisted he wasn't joking.

He said: "It's not a joke.

"This I wouldn't joke about. I love you so much and this show's meant so much to both of us. ... Why not make it official now? Will you honey? Will you accept?"

She wept and said: "Yes, yes, yes! Oh, my gosh! Of course! I can't believe this is happening!"

"Oh, my God! This isn't happening right now! Honey, are you serious right now? Oh, my God! I love it. Oh, my God! It's amazing. Thank you. Oh, my god!"

And the E! News host was thrilled with Kevin's choice of engagement ring.

She laughed: "Oh, my God! This is so beautiful, and I hate engagement rings! I think they're so ugly--for me!"

After she put on the ring, Maria's parents Costas and Litsa Menounos entered the studio.