Blake, who lives in Denver, CO, proceeded to get all bundled up in his winter clothes, telling the cameras that it was "freezing" outside.
"The sh-t you do for love," Blake joked.
Blake then spelled out "Will You Move In With Me?" in the snow outside of his house. He asked Giannina, 29, to reply "yes" or "no" by making a snow angel in the yard.
"OK, it's actually super cute," Blake bragged in his video, before jokingly making gagging noises, suggesting the love fest would make a person sick.
The Atlanta native then walked outside.
"I got a surprise for you! Baby, I have a question for you," Blake said.
"Will you marry me?!" Giannina incorrectly guessed.
Once Giannina read Blake's invitation, she said, "Aww," and hesitated for a moment.
"I'm still thinking about it," Giannina teased her boyfriend.
But then Giannina got down in the snow and made her snow angel, which prompted Blake to yell, cheer and celebrate the news. The couple kissed in the snow and appeared to giggle about becoming roommates.
Blake set the sweet video to "Isn't She Lovely" by Mount Hayes.
Blake and Giannina went Instagram official in early April while they were on a trip to Spain, several months after reports began to swirl about the couple dating.
Blake and Giannina -- who called Blake her "worst kept secret" in June -- had to keep their relationship, which began in late 2021, under wraps for a while because they had met on a Paramount+ reality show called All Star Shore, which filmed in December 2021 and didn't premiere until June 2022.
"They're taking things slow. But [they] seem really happy together," a source told People at the time.
Romance rumors sparked when eagle-eyed fans noticed Blake and Giannina were posting photos with similar backgrounds on social media.
Blake, for example, posted a photo of himself sipping on cocktails in front of a big wooden barrel at Mile High Spirits in Colorado on New Year's Eve, and Giannina's Love Is Blind co-star Kelly Chase commented, "Happy new year."
Giannina subsequently posted a picture of herself posing in front of similar barrels the next day.
Giannina, wearing a sexy white dress at the time, captioned her post, "Repeat after me: I am about to walk into the best year of my life."
One fan account, @myteaandroses, also pointed out how it appeared Giannina had uploaded an image from Blake's bed via Instagram Stories on New Year's Day.
And a few days prior, Giannina revealed on Instagram that she was about to travel from Miami "to the mountains," hinting she was headed to a colder destination on December 28.
Giannina got engaged to fellow Love Is Blind contestant Damian Powers on the show in 2020, but during the season finale, Damian reportedly admitted at the altar he couldn't go through with marrying her so soon.
The pair chose to stay together and continue dating, but then Giannina announced in August 2021 she and Damian had split.
"I am officially single. Me and Damian haven't been dating for a couple of months now," Giannina told Entertainment Tonight at the time.
Giannina said she had "moved on" from Damian at that point and felt "really, really good" about where she was at in life.
During the Love Is Blind: After the Altar special that was released last year, it was revealed that Giannina and Damian had reportedly been facing problems, such as Damian's too-close relationship with Too Hot to Handle star Francesca Farago.
(According to People, however, Damian denied any romantic involvement with Francesca).
As for Blake, his breakup with Becca on The Bachelorette finale in August 2018 was excruciating to watch considering Blake had said he was madly in love with the show's leading lady.
Blake was admittedly "blindsided" by Becca's decision to dump him because he appeared to be her frontrunner all season long.
"I truly thought that if it came down to me proposing, that she wouldn't say no," Blake told ET in 2018. "I thought what we had was real."
Blake added it was "incredibly hard" to get over his heartbreak at first.
Blake then appeared on Bachelor in Paradise's sixth edition and came across like a playboy.
He was romantically interested in Hannah Godwin on the ABC spinoff, but she chose to pursue a relationship with Dylan Barbour instead.
Blake said on Instagram in Summer 2021 that he has no interest in appearing on the franchise again for the sake of his mental health because he believes the franchise "breeds toxicity and emotional abuse."