Jessica Simpson stood up two dates on Tuesday night – boyfriend Tony Romo and ... Elmo?

The singer – who designs clothing, shoes and handbags for Macy's – was supposed to fly from Nashville to New York Tuesday to celebrate the department store's 150th anniversary.

But driving rain caused serious flight delays, forcing Simpson to miss her scheduled gig singing "Happy Birthday" with Elmo.

In fact the Macy's party – which included guests like Eva Mendes, Tommy Hilfiger and Martha Stewart – had nearly ended by the time Simpson finally arrived at 8:30 p.m.

"I'm so, so sorry!" she said as she rushed into Gotham Hall with her B.F.F. hairstylist Ken Paves. "[I wish] I could be God and control the weather."

But her injured NFL boyfriend, for one, was hoping she'd miss the event.

"Tony was just praying [that I wouldn't make it out]," Simpson admitted. "He had planned a really romantic date in case I didn't make it [to New York] tonight."

And while a date night was tempting, "I decided to come," she continued. "I'm like, 'Honey, I have to go.' "

So what make's the quarterback such a catch? "His heart!" she told PEOPLE. External Image