The 24-year-old actor and comedian recalled his "really dope" proposal to Grande in an interview with Variety published Tuesday.
"I didn't want to do something corny," Davidson told the magazine. "We were in bed hanging, after watching a movie. I was like, 'Will you marry me?' It was really dope."
"I'm still convinced she's blind or hit her head really hard," he said of the 25-year-old singer's acceptance. "For right now, it's rocking."
Davidson and Grande confirmed their engagement in June after a few weeks of dating. Davidson said he didn't plan to marry prior to his relationship with the "God is a Woman" singer.
"I never thought I'd meet anyone like her," the star said. "I can't even put into words how great of a person she is. I could cry."
"I feel like I'm living in a fantasyland," he added.
Grande and Davidson made their red carpet debut as a couple at the MTV Video Music Awards last week. Grande thanked Davidson during her acceptance speech for Best Pop Video for "No Tears Left to Cry."
"Pete Davidson, thanks for existing," she said.