Carrie Underwood shows off diamond and ruby necklace – a Valentine's gift from hubby Mike Fisher

Carrie Underwood and Mike Fisher are definitely Valentine's Day goals! During Sunday night's Grammy awards, the "Smoke Break" singer showed off some serious bling, gifted to her by her sweet husband over the recent romantic holiday.

Inspired by her hit song of the same name, the diamond-encrusted "Heartbeat" necklace features 20 carats of rubies, and it’s centerpiece is a flawless yellow 12-carat diamond named the Firefly.

"It was a Valentine's present, that I don't deserve, " Carrie shared with ET online. Carrie's diamond encrusted necklace with colored gems paired well with her sleek black Nicolas Jebran gown.

Carrie gushed about being able to wear her new jewels whenever she wants. "It's mine to wear, so whenever I feel like it," she said about the gift from her hockey star spouse. "I can be in my sweat pants, making dinner, wearing my necklace."

She continued: "I kind of knew it was coming. We had been helping and working with designer Johnathon Arndt to make something special. We don't do a whole lot of gifts often, it was nice. This is many years' worth of gifts."

In the spirit of gifts, Carrie and Mike are prepping for their son Isaiah's first birthday on February 27. The American Idol alum admitted that she isn't quite sure what to get her little boy for his milestone bday.

"I'm like, what do you get a 1-year-old for a present?," she quipped. "I have no idea so I've been on, like, Amazon trying to find presents for him. I'm gonna have to just go to the store and look. People are like, 'What is he into?' I'm like, 'I don't know, he's one!"

Carrie did share that her little boy, who recently took his first steps before joining her on the "Storyteller" world tour, will be in good company when it comes to celebrating his big day.

"A little party," she said. "Just family and friends, people that are staples in his life -- it won't be anything fancy."