Mark Willey (left) hugs his new fiance Bianca Caram after he proposes her on a float at the Dallas St. Patrick's Parade in Dallas.

Mark Willey (left) hugs his new fiance Bianca Caram after he proposes her on a float at the Dallas St. Patrick's Parade in Dallas.

Jae S. Lee/Staff Photographer
Bianca Caram (right) shows the crowd a ring after Mark Willey proposes to her on a float with a big sign that says "Marry Me B?" at the St. Patrick's Parade on Greenville Avenue in Dallas on Saturday, March 11, 2017.

Bianca Caram (right) shows the crowd a ring after Mark Willey proposes to her on a float with a big sign that says "Marry Me B?" at the St. Patrick's Parade on Greenville Avenue in Dallas on Saturday, March 11, 2017.

Jae S. Lee/The Dallas Morning News

She said "yes." Then she said, "you're crazy."

Dallas man Mark Willey proposed to his girlfriend Bianca Caram wearing a green shamrock suit during the famed Dallas St. Patrick's Parade and Festival. An estimated 120,000 people were expected to attend the annual bash, and many of them saw Willey's "Marry Me B?" float go down Greenville Avenue.

Caram, of course, didn't see it until it landed at one very calculated place along Greenville Avenue: Where she was standing. She spotted Willey wearing an outrageous green suit as two pals hoisted her over the guardrail toward her shamrock prince.

Taylor Swift's "Love Story" erupted from the speaker, confetti cannons ignited and Willey asked the big question. She didn't see it coming, she says.

"It was seriously the most millennial proposal of all times," says Willey, who is a digital manager for 7-Eleven. Caram is an OB-GYN doctor at Legacy Women's Health.

Celebratory cups!

Celebratory cups!

Benjamin M. Robinson/Dallas Morning News

He had been sweating the weather forecast all week. But with a little luck of the Irish, the weather in Dallas was sunny and beautiful.

Willey had been working for eight months to carefully construct his master proposal plan. "St. Patty's Day is our favorite weekend in Dallas," he explained. "And Dallas is where we are going to build our lives. It seemed kind of wild and outlandish but it was me and I went for it."

He knew it would be no trouble getting Caram to the parade, as they have attended it together during their courtship previously. He just needed to slip away and catch up with the float. Although Willey had meticulously timed out the parade route, the parade moved faster than he anticipated and he had to hustle. He also had to change -- quickly -- into his shamrock suit.

"The whole crowd was cheering," Willey said.

Here's the happy couple, Mark Willey and Bianca Caram.

Here's the happy couple, Mark Willey and Bianca Caram.

Jae S. Lee/Staff Photographer

After the parade, the newly engaged couple gathered at their home with 50 family members and friends for a St. Patrick's Day celebration slash impromptu engagement party.

"We will spend the rest of the day with our family and friends drinking green beer, eating tacos from Taco Joint and playing lawn games," Caram said.

But Willey had one more surprise up his shamrock suit sleeve: He hired a mariachi band to serenade Caram at the party.

So when's the wedding? The couple -- who met on a blind date -- is planning a destination wedding in Mexico in 2018.

By KIMBER WESTPHALL/SPECIAL CONTRIBUTOR

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