Bernie Sanders isn't giving up on his mission to become president. But on Sunday he made a pit stop - well, a video stop - to help a campaign staffer accomplish his mission to marry.

Sanders made a video for Hector Sigala, the campaign's social media director, to play when he popped the question to his long-time girlfriend, Kimberly Riofrio.

They were tricky about it. Sigala played it cool, pretending that he was just showing Riofrio another Sanders social media video. Because he carefully creates and curates Sanders videos all the time this was a pretty plausible Sunday afternoon activity. At the beginning of the video Sanders is talking about the state of his campaign. Then, Sanders slyly switches it up.

"Oh wait a second. Hey, Rio, Hector has a question for you. He's a good guy. Why don't you help him out," Sanders says with smiling eyes.

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Sigala took it from there.

"By the time she realized this was a video made for her, I was on one knee with the engagement ring out," Hector told CBS News. On that perfect Sunday afternoon at park in Pasadena, Marlyand next to the Chesapeake Bay beach, Riofrio said yes.

Weaving Sanders into the proposal fits in to with Sigala's life right now - one that has been wholly consumed with campaign work for over a year. But Riofrio also loves Bernie Sanders, and the feeling is mutual.

"Whenever I see Bernie, one of the first things he asks - right before asking how our last social media post is doing - is about how Rio is doing. I was really glad he was willing to film this short video and be part of the proposal despite his very busy campaign schedule," Sigala said.