Selena Gomez and Benny Blanco toast their engagement in a behind the scenes video set to one of her songs

Selena Gomez and Benny Blanco toast their engagement in a behind the scenes video set to one of her songs

The music mega-producer soundtracked their champagne toast with fitting lyrics from Gomez’s 2015 song “Good for You”.

Blanco, 36, shared an Instagram video on Saturday, Dec. 14, of the happy couple clanking champagne glasses together.

In the very short clip, Gomez, 32, smiled widely and her engagement ring sparkled as she toasted her fiancé, who had proposed on Wednesday Dec. 11.

The music mega-producer soundtracked their champagne toast with Gomez’s 2015 song “Good for You,” specifically with the part where she sings, “I’m on my marquise diamonds.” Fittingly, Blanco proposed to Gomez with a large marquise diamond set on an eternity band.

The toast appears to have occurred during their Dec. 11 engagement picnic, which included Gomez’s favorite meal from Taco Bell.

“It was very her,” a source exclusively told PEOPLE about the special moment. “It was a total surprise to Selena.”

Later in the evening, the couple had an “impromptu gathering” with their friends and family to celebrate their occasion, the insider added.

“Benny and Selena were so excited to share the news right away with their loved ones,” the source said. “It’s such a true partnership between them.”