Ariana Grande and Pete Davidson's Friends Are Cautious About 'Spontaneous' Engagement (Exclusive)

A source tells ET that while Ariana Grande and Pete Davidson's friends are not surprised at their whirlwind engagement, some are a bit concerned.

Ariana Grande and Pete Davidson are engaged after a few weeks of dating, ET learned on Monday, and a source tells ET that while their friends are not surprised at the big commitment, some are a bit concerned.

The singer and the Saturday Night Live star, both 24, began their whirlwind romance late last month, following their respective splits -- Davidson from Cazzie David and Grande from rapper Mac Miller. 

"Ariana gets so excited about an idea and so set on making it happen that she doesn't always think it through," the source says. "We of course want her to be happy, but this was a very quick lifetime decision. It's a little worrisome and we fear it was so spontaneous it might not last. One thing is for sure, Peter does look very much in love, and while they are young, they are certainly old enough to make this decision on their own."

The source notes that the two are definitely "head over heels" for one another.

"Ariana and Pete have so much in common it's doesn't surprise all their friends," the source says. "They've both been through so much and are able to share openly what they have faced and support each other with understanding. Ariana and Pete are both passionate and impulsive and fell head over heels for each other. They didn't hesitate to share their love and their commitment for one another with their friends and with fans on social media."

"Peter is an old soul and always has known what he wants, so some friends aren't at all surprised this happened so fast," the source adds.

The source also says the pop star relates deeply to the comedian.

"They are both so passionate and swing back and forth from strong, loving moments to heated arguments ... Peter is the sweetest person in the world and he is just dealing with a lot psychological challenges," the source claims. "Ariana feels right now she can relate to his pain and that they have connected on many levels."

Davidson revealed last year that he was diagnosed with borderline personality disorder. Last month, he took to his Instagram Story to defend himself against those commenting that his mental illness prevents him from being in a successful relationship. 

"Normally I wouldn't comment on something like this cause like f**k you," he wrote. "But I've been hearing a lot of 'people with BPD can't be in relationships' talk. I just wanna let you know that's not true. Just because someone has a mental illness does not mean they can't be happy and in a relationship. It also doesn't mean that person makes a relationship toxic." 

"I just think it's f**ked up to stigmatize people as crazy and say that they are unable to do stuff that anyone can do," Davidson continued. "It's not their fault and it's the wrong way for people to look at things. I may be crazy but at least I'm aware of it and not afraid to be honest about it and I'm not hiding behind a Twitter or Instagram account."

On Monday night, Grande and Davidson enjoyed a late-night trip to Disneyland in Anaheim, California, following the news of their engagement. A source described the couple's relationship to ET on Monday as "intense."

"The combination of a girl who is yearning to be loved and mixing it with a guy like Pete creates this intense relationship that is moving a million miles a minute," the source said. "For both of them, this relationship is heaven compared to their past relationships and they're just clinging to that heaven and thrilled about it."

For more on Grande and Davidson's whirlwind romance, watch the video below:

-- Reporting by Adriane Schwartz

RELATED CONTENT: