David Drury, 28, got down on one knee in the crowd outside the " Good Morning America" Times Square studio today and popped the question to girlfriend Trisha Hearn, 30, of Austin, Texas.

"Oh my god, this is not happening," Hearn, 30, said in shock before dropping down to the ground to embrace her husband-to-be with a huge hug and kiss.

"I guess that's a yes?" "GMA's" Lara Spencer asked.

"A big yes!" Hearn exclaimed.

Drury, a physician's assistant in Houston, and Hearn, a patient coordinator at a doctor's office in Austin, are both "GMA" fans and were visiting New York City on their Christmas vacation.

"Trish loves the show and loves New York, so I thought, let's give it a shot," Drury told us afterwards. "I was pretty nervous, pretty antsy….but it was more amazing than we could have ever expected."

Over Thanksgiving, Drury let Hearn's mother, grandmother and sister in on his secret proposal plans. Hearn said she that she had "no idea" the proposal was coming.

The couple, who met a year and a half ago through a mutual friend, plan to celebrate their engagement in New York City this weekend. They said they want a big wedding, surrounded by family and friends.

"All we know is that it's going to be a big wedding," the bride-to-be said. "It's going to be a big party!"