He once filled her blank space, baby! Taylor Lautner revealed to his Scream Queens costars John Stamos and Lea Michele that his ex-girlfriend Taylor Swift wrote the track “Back to December,” from her 2010 album, Speak Now, about their brief relationship.

During a Facebook Live chat at the Television Critics Association press tour in Beverly Hills on Tuesday, August 9, the trio candidly recalled Lautner’s former romance with the “Shake It Off” singer, 26.

"I exposed who Taylor dated earlier in one of the interviews,” Stamos, 52, brags to Michele, 29, in the clip above.

"You mean in life or on the show?" the Glee alum asks the Fuller House star before turning to Lautner, 24: "Who'd you date in life?"

Completely embarrassed and red-faced, the Twilight hunk replies, “I don’t know.”

After some banter about Lautner’s past relationships (exes also include Maria Avgeropoulos and Lily Collins), Michele finally brought up Swift’s name. “You dated Taylor Swift,” she teases her bashful friend. “I remember that.”

Lautner’s response? “That’s hilarious,” he says in an attempt to change the subject. However, the Brunette Ambition author continues to press the Grown Ups 2 actor about his time courting the country cutie turned pop superstar: “Should we talk about it?”

"No!" Lautner says. "I don't know why you guys want to talk about it."

"Didn't she write a song about you?" Michele questions.

"That's what she does," Lautner reasons. "She writes songs."

Next, Stamos — who is not much of a Swiftie and rather unfamiliar with the Grammy winner’s discography — asks which tune was inspired by Lautner.

"I think it was on the one about a sweater and a hat," Michele replies as Lautner starts to squirm, and offers, “[Taylor Swift has] good music. I listen to it.”

Despite Lautner’s discomfort, Michele keeps the conversation alive and makes an attempt to recall which song Swift penned about her pal. “Something about, 'If I would have known / I wouldn't have done that / I'll make you a hat,'" she says, " … Something about a hat! I don't know!"

Eventually, Michele gets it right. "It's like your hat … in December!" she exclaims. Lautner gives up and admits, "It's called 'Back to December.'"

As previously reported, Lautner and Swift dated for several months starting in October 2009. Sparks first flew when they met on the set of the film Valentine’s Day, but their romance fizzled after only a few months and was over by that following December.

Watch the hilarious video above.

Want stories like these delivered straight to your inbox? Sign up now for the Us Weekly newsletter!