Pete Davidson and Ariana Grande. Picture: Instagram

Washington - There are plenty of reason to be skeptical of Ariana Grande and Pete Davidson's recent engagement. 

The pop star and Saturday Night Live comedian are both young (24). Davidson has gone all-out on the rock; he reportedly spent $93 000 on a custom-made engagement ring for Grande. 

They've had an accelerated courtship - dating for about three weeks before getting engaged (though some dispute that timeline) - and both got out of long-term relationships recently, a hallmark of a rebound.

In an attempt to understand Grande and Davidson's relationship, we spoke to four couples who got engaged in a matter of weeks or months.

Richard and Brittney Settles got engaged after a month of dating

Richard had never dated one his sister's friends before. "I just knew that would be trouble," he recalls. But when he met Brittney at a party at his sister's place, when they were both 21, she seemed different, he says, and therefore worth the risk.

After they met, Richard remembers taking Brittney out for a lot of meals, but they weren't dating per se. Shortly thereafter, he was deployed to Iraq with the Air Force - and when he got back four months later, in January 2008, "that's when things really got serious," he recalls. He went down to North Carolina to meet her family (he remembers being scared of her uncles!), but he also became close with her mom and aunt. "I just knew if I was to get married, she'd be the one," Richard remembers.

A month in to dating, Richard proposed. And he thinks his military background has something to do with the speed of their courtship. "Maybe I thought I was going to get deployed again," he recalls. "In the military, you have to think fast. I've known people for two weeks and they end up being your really good friends. Anywhere else, you don't do that."

Richard and Brittney now have three kids, and they're planning a 10th anniversary trip to Italy. 

Mickey Bergman got engaged to Robin Levine Bergman after 5 months of dating - and they only spent 5 weeks of that together

Mickey and Robin met at a Jewish summer camp for adults, and their first conversation was a heavy one: Would you adopt kids or carry one yourself? "Don't you want a little girl with your face on it?" Mickey, 24 at the time, remembers asking Robin, who was 23, during a hike with several other campers. Robin, who is adopted, planned to go that route for herself one day.

Even though they barely knew one another, it felt like the beginning of negotiations over what their own family might look like. Robin describes feeling a magnetic pull toward Mickey. "I always wanted to know where he was in the room," she recalled of their time at camp.

After camp, Mickey, who lived in Israel at the time, spent a week with Robin in Los Angeles. When he flew home, they decided to try a long-distance relationship. Right then they knew: "The only way it can work is if we have a time where we know it will no longer be long-distance," Mickey says, and that conversation led them to getting engaged five months after they met.

Then the secret-keeping began

"Part of the engagement agreement was not to tell anyone, because everyone thought (our relationship) was ridiculous," Robin recalls. "I was concerned about people's opinions. I was 23. ... We were living 7 000 to 8 000 miles apart," and they didn't know who was going to move where to bridge the distance. "I had always thought I would have a career first and get married at 38 or 40," Robin says. But "I was surprised how strongly I felt about marriage once I met Mickey."

However, they did tell their parents about their engagement. Mickey's folks were instantly thrilled and Robin recalls telling her parents on speakerphone with Mickey sitting beside her. Her mother burst into laughter at the news (she assumed Mickey just wanted a green card), Robin says, while her father very calmly explained that this was a big mistake.

But it wasn't a mistake. Mickey ended up moving to Los Angeles; they got married in 2002. 

Five months into Lauren and Samim Syed's relationship, they faced a decision: Get married, or Samim would have to leave the country

In summer 2015, Samim and Lauren were on the same group trip to Greece; they didn't meet but they did make the same friends. Over a year later in New York, they were at brunch with those mutual friends - and hit it off.

They started dating immediately. "At our one-month anniversary dinner, we were already talking marriage and kids. We both just knew this was it," Lauren says. "I just had this sense of peace when I looked at him." She added that they had met in Greece, it probably wouldn't have worked out. But in New York, "we were both at a period in our lives where we were ready to find the right person."

Samim, who's from Britain, was in New York on a work visa. But then he got laid off and his immigration lawyer asked: "Are you going to marry Lauren? You need to do it now." So they went to city hall and became husband and wife. "We probably would've been engaged in the next couple of months anyway," Lauren says.

They were worried about what people would think, especially their parents, and wanted to just enjoy the decision they'd made together, Lauren says. But both sets of parents could just tell how happy the two were together.

Quick courtships aren't common in the United States, Lauren says, because "there's a lot skepticism around marriage," plus it's a big commitment.