Taylor Swift and Emma Stone have been pals since 2008, which is why fans believe that "When Emma Falls In Love," one of the "From the Vault" songs on Speak Now (Taylor's Version), is about the Oscar-winning actress.
Specifically, fans are convinced the song is about Stone's relationship with either Kieran Culkin, who she dated from 2010 to 2011, or Andrew Garfield, who she was with from 2011 to 2015.
Fans point to the line in the song where Taylor sings, "When Emma falls in love, she calls up her mom, jokes about the ways that this one could go wrong." Apparently Emma has a very close relationship with her mom.
Taylor wrote "When Emma Falls in Love" at the same time as the original Speak Now album, which she composed between 2008 and 2010. Therefore, it's unlikely the song is about Stone and Garfield; Culkin seems to be the better bet.
In any case, Taylor and Emma are still buddies: She recently told Vanity Fair that Taylor hooked her up with tickets to one of her Eras Tour shows, and added, "She's a wonderful friend. She blows my mind."