Arthur Kasabyan got a little help from the LA Rock Choir to put on a flash mob-style performance.
Out of nowhere, they started singing "Marry You" by Bruno Mars.
Kasabyan's girlfriend didn't know what was happening until her now-fiance dropped to his knee and asked a very important question.
"From kindergarten, to best friends, to finally being lovers. Baby, will you please be my forever?"
The crowd cheered as his emotional partner said yes.
[Ads /]
Kasabyan said the choir spent the last four weeks rehearsing for the big surprise.