"We went on a double date, bowling and karaoke. He kissed me at the bowling alley," she recalls. "I told my security to step outside 'cause I didn't want to be watched."
"He was the best kisser ever," she adds. "I know I'm really good at kissing, but I was shocked when he was."
The 23-year-old pop star, who first sparked dating rumors with the former Spy Kids actor last October, admits she "never really felt sexy with guys before." But that all changed when she met Sabara.
"No one expressed how they liked my body out loud in the bedroom until I met Daryl. He is obsessed with it -- every inch," she gushes. "And that has improved my confidence more than even 'Bass' did. He's a champion, so we're in heaven."
Trainor is currently working on a new album, and says many of the songs she's written so far are inspired by her beau.
"I wrote six songs on the road about him in front of his face," she teases. "One is called 'Marry Me.'"
Trainor echoed those sentiments while chatting with ET at the Smurfs: Lost Village premiere in Culver City, California, earlier this month.
"[Daryl] says he likes my kind heart, he likes that I care about people," she said. "I was like, 'Stop it, you're so cute, I care about you.' He's around here somewhere [and] he just keeps walking by me going, 'You're beautiful!'"