The first day that Michael Alvarado met Carissa Rae, he knew he was going to marry her.

“I left and I get back in the car with my college roommate, and I turn to him and I say, ‘I am going to marry this girl.’ And he’s like, ‘What, are you crazy? You’ve only known her for three hours! How could you possibly know that?’ And I told him sometimes when you know, you just know. And I knew it with her,” Michael tells PopCrush in our studio, where he and Carissa are filming a live performance for our #NextUp series, which highlights the new music artists that you need to know now.

Michael, who grew up a piano-playing kid in North Carolina that fell in love with jazz and John Mayer (and accidentally discovered he could sing when his high school band’s frontman got sick once), and Carissa, who was born into a choir-loving family and idolized Beyonce’s crazy vocal and dance skills while growing up, make up the male-female pop pair Us the Duo, perhaps best known so far for their Vines. They’ve covered just about every recent pop song you could think of in only six seconds -- their “Best of Taylor Swift” mashup seems to be one of their most popular covers -- and people having been taking notice: new fans, ‘Good Morning America’ and record labels. Now, they’ve signed with a major label and re-released the album ‘No Matter Where You Are’ on May 6.

But for Michael and Carissa, love comes before anything else. Watch them interact online, onstage or while just chatting when the camera is not rolling, and you’ll see that this -- the chemistry, in music and as a couple -- is not an act. These are two people who grew up across the country from each other, yet it somehow feels like they were really meant to cross paths. If it hadn’t happened at one fateful music video shoot, it probably would’ve happened in some other way.

They realized they had a connection after first meeting as extras on set in Los Angeles. When they tell this story, they don’t mention any details about the artist or the song that the shoot was for because they’re too busy remembering how much they were flirting with each other.

Watch them interact online, onstage or while just chatting when the camera is not rolling, and you’ll see that this -- the chemistry, in music and as a couple -- is not an act. These are two people who grew up across the country from each other, yet it somehow feels like they were really meant to cross paths.

“All of the sudden out of the dust, this little Filipino girl comes through the wreck and was like, ‘Hi, I’m Carissa,’" Michael recalls.

“I don’t sound like that, though. I don’t,” Carissa says.

“A little bit. ‘Hi, I’m Carissa,’” he tries again.

“Nope, you need to work on that,” she quips.

“’Hi, I’m Carissa, it’s so great to meet you,’” Michael continues. “’Let me show you the world.’ Well, the people. You did show me the world, kind of like Jasmine. So we walked around, we hit it off and we laughed. We weren’t even paying attention to this music video. The director probably hated us.”

They soon found themselves in a modern love story: Michael pursued Carissa through tweets, the two really got to know each other over AIM conversations, and when things got more serious, they spent hours and hours on Facetime together.

“My excuse to getting on Facetime with her was writing a song together,” Michael says. “Keep it kind of professional. It was called ‘Missing You Like Crazy,’ and we ended up singing the song for five minutes and chatting for six hours. So at that point we both knew.”

“I finally realized in that moment on Facetime, ‘Wait, I’m going to marry this guy. WHAT?” And then I felt the feeling where you just know,” Carissa agrees. “It just matches. Everything is aligned. Your head, your heart, your soul … I’m like, ‘Yep, I’m going to marry him,’ and we just started talking about our future. It was really crazy.”

Watch Us the Duo Perform 'No Matter Where You Are'

What comes next in their story is even crazier. After realizing that they’d found something special with one another musically, too, thanks to great success (read: millions of views) as YouTube artists, they discovered a creative way to cut through the noise with their music: distributing it in a very Us the Duo way on Vine, with only half their faces showing in every six-second song clip.

“We [had] just put out a record. How are we going to market this?” Michael recalls, setting the scene for the night that the next chapter of their career began. “Let’s try Vine. So it was a late night, and I said, ‘Hey, baby. Let’s do a cover of John Legend, ‘All of Me.’ Right now. We’ve gotta do this now. No one’s on Vine singing music. Now is the time!’”

“And I was ready for bed,” Carissa admits. “I had my PJs on, I had no makeup, I was just eating popcorn on the couch. I was like, ‘No! What? I don’t wanna do that right now. I’m ready for bed. I don’t want to film anything. I don’t have makeup on. I don’t look presentable.’ And he was like, ‘Oh, it’s fine. We’ll just, we’ll not show our eyes. We’ll film from the nose down, and you can just put on another shirt and you’ll be good. They won’t even see your pajama pants. It’ll be great.’ And I’m like, ‘OK. Let’s try this.’”

“So we put out our first Vine,” she continues, “and it did pretty well, and we continued to do it every single day and just stuck to the half face thing ‘cause it was kind of our brand. Next thing you know, we’re on the popular page and Viners are seeing us and they’re re-Vining and promoting us, and our followers just skyrocketed. We started at 4 or 5,000, and now we have 2.9 million followers. It just kind of went out of nowhere and blew up like that.”

Us the Duo are a likeable people, and if you need any proof of that, check out how many views and happy comments videos of their proposal and marriage have counted on YouTube. (For the record, that’s 719,000+ views and almost 500,000 views, respectively.) Their new single, the feel-good title track of the ‘No Matter Where You Are’ album, speaks to the lack of barrier between their lives off and on-screen. The love song, with lyrics like “I will hold on to everything we’ve got / A quitter and regretter and forgetter is everything I’m not / I’ll take care of you, love you just because / You and I are better than forever / Nothing can stop us,” doubled as their wedding vows.

“We wrote the song just a few weeks before our wedding, and the wedding vows kind of came out of the song. We didn’t write the song with the intentions of that being our exact wedding vows, but I remember we split up, like ‘We really need to write these vows, this is important!’ And we sat down and started writing … and I basically wrote all the lyrics to our song, so [I thought] we should just sing this at the wedding, as cheesy as this sounds,” Michael says.

“We always said we wouldn’t sing at our wedding, but we ended up doing it anyway,” Carissa adds.

Watch Us the Duo Perform 'Til the Morning Comes'

With anyone else, performing at your own wedding might sound pretty cheesy, but it somehow works for a couple that seems as go-with-the-flow and genuine as Michael and Carissa. Michael jokes that their family “all hated it and threw tomatoes at us. White dress ruined by tomato juice,” but this is coming from a guy who claims he’d run his fingers through John Mayer’s hair if his fantasy of meeting his musical hero ever came true.

What’s next for Us the Duo? After releasing ‘No Matter Where You Are,' they’re setting their personal and professional goals high: hoping for a family and a Grammy.

“Having kids and settling down into a stable life is something we’ve always wanted to do, and Republic can help us have a healthy balance of putting our family first and letting our music be just a business, but a passionate business for us,” Michael says. “We’re excited to see how that will play out in the next five to 10 years. Hopefully, we can have twins. We want twins so we can be Us the Duo’s duo. So then all our Vines will be our faces here, and our little baby’s faces right above us, like a four Vine thing. We’ll be like the Von Trapps, but the Von Duos."

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