"I listen to his music probably more than I should. It's maybe slightly creepy," Biel, 34, quipped during the episode that airs Thursday. "I love his music. I'm literally probably [his] no. 1 fan."
Adding that their almost 1-year-old son, Silas, also is into his daddy's tunes, Biel noted, "I went to probably 40/ 50 concerts when I was pregnant. I literally just stood there and the music was just slamming. I thought, 'I'm going to damage this child.'"
Thankfully she didn't, and as Silas nears his first birthday, he's already showing signs of following in his father's footsteps.
"[He's] very musical," Biel said of her little boy. "He's really, really in love with Erykah Badu. He loves her music. He eats to her music. He's got just recently these drum sets. He likes to drum; he likes to play with his piano. And he likes to drum with his head… which I just think that's genius, if you ask me. That's genius level."
Though she has yet to celebrate her son's birthday, the 7th Heaven alum is already fielding questions about a second pregnancy.
"I know, isn't it exciting, guys?!" Biel joked of her fake pregnancy as the audience cheered. "I don't even know what to say about these things. I feel like, man, I thought I was doing good with my yoga practice. I thought I was in the gym, but no, I have a gut, apparently... Yeah, twins."
Just because they're not expecting doesn't mean that Biel and Timberlake don't still have that romantic spark. The actress recently talked to ET's Joe Zee about her ideal date night.
"I kind of like an old-fashioned date -- dinner, movie, make out," she said. "That's like a great date!"
The couple recently lit up the Vanity Fair Oscars after party in February, and earlier this month, Timberlake posted a sweet message in honor of his wife's birthday.
"Happy BAE-DAY, baby!! I can't put into words what you mean to me… You are the GREATEST Mommy and Wife a man could ever ask for. I love you to the MOON AND BACK!! – Your Huz," he captioned a kissing pic.