Host Jimmy approached the conversation by telling the 24-year-old he "didn't have to get engaged to Ariana Grande to come on our show". "So sick", said Davidson.
"I feel like I won a contest", the Saturday Night Live star, told Fallon.
The Saturday Night Live star addressed the reports and confirmed the engagement with the "The Light is Coming" singer after a whirlwind romance of just a few weeks, during an appearance on The Tonight Show on Wednesday. As they take their love to the next level, a source told ET that the two are now "living together" in a lavish apartment in New York City. It's so amusing when you're walking down the street, and dudes, they're like (tipping their hats).
She was spotted wearing a ring which people thought was one which Davidson made her wear. "Some dude came up to me and he was like, 'Yo man, you, like, gave me hope'".
Grande, on her end, is equally as smitten and posted an Instagram Story of her beau on Wednesday, writing, "a flawless specimen".
His Instagram has also since become a Good Time fan account with a couple posts featuring Robert Pattinson's character: including a photo of the shirt he wore on the show which seems to be a still from the film.
Ariana and Pete reportedly began dating in May after Ariana's breakup with Mac Miller.
Her new fiancé - an actor and comdian best known for his sketches on SNL - split with Cazzie David, the daughter of comedian Larry David, in May.