Boston Celtics point guard Marcus Smart sent the Twitterverse into a tizzy on Sunday, just hours after the team's convincing win over the Milwaukee Bucks.

In a series of cryptic posts, the reigning Defensive Player of the Year hinted that his days in Boston were numbered, but then delivered the surprising punchline that he had just popped the question to longtime girlfriend Maissa Hallum.

At 10:56 p.m. on Christmas Day, Smart took to Twitter to announce to his near half-million followers, "I’ve had enough. Been holding it in too long and it’s about time this gets said..."

Three minutes later, he added a splash of gasoline to the fire, writing on Twitter, "It’s time for me to leave..."

But just as Celtic fans were starting to panic, Smart's post from 11:01 put them at ease. Along with a photo of him and Hallum wearing matching holiday pajamas, Smart dropped the big news.

"Oh I forgot the rest… Time for me to leave the single life," he wrote, adding, "She said YES!!! (Whew)"

In the photo, Hallum is proudly showing off her new engagement ring, featuring what appears to be a large princess-cut diamond set on a diamond-accented band. As of this writing, Smart's proposal announcement has been seen 15.2 million times on Twitter.

On his Instagram page, Smart shared a video of the actual proposal, which included a pre-taped guest appearance by actor Will Smith.

Smart, Hallum and other guests are all together in Smart's home theater as Smith appears on the big screen with a holiday message shot from Antarctica.

"We’re coming back from the South Pole, but I just wanted to take a minute," said Smith, who is dressed in cold-weather gear. "I wanted to wish you a very, very Merry Christmas. Now, I know that you may not have gotten the stuff that you wanted. I promise you, you’re not going to end this Christmas empty-handed, OK. That’s all my message is."

Hallum, who seems to be amused, but also a bit confused by the celebrity's message, doesn't notice what is happening right behind her.

Smart taps her on the shoulder and she spins around to see the Celtics star on bended knee with a ring box in hand. At first, a shocked Hallum turns away with her hands over her face, but then embraces her boyfriend and accepts his proposal.

On Instagram, Smart wrote, "She said “Y E S”! (Whew!) Thanks @willsmith for the setup help!"

You can check Smart's Instagram carousel, which includes the heartwarming video, here

Credits: Screen captures via Instagram / youngamechanger.