The "Blank Space" singer expressed her support for her longtime BFF over the release of her new song "Single Soon" on her Instagram Stories Aug. 26.
"When ur bestie is the bestest," Taylor wrote, under the single's music video.
The pop star, who earlier this year went through a breakup with actor Joe Alwyn following a six-year relationship, and months later, ended a whirlwind romance with 1975 singer Matty Healy, added, "Will be dancing to this forever methinks."
On Aug. 26, Selena reposted Taylor's post on her own Instagram Stories.
She also recently thanked her fans for their support over the song's release. "Thank you guys for all the love on Single Soon!!!" she wrote on her Instagram. "It's a playful anthem about being comfortable in your own skin and loving your own company… and it's also really fun to dance to!"
"Single Soon" was released Aug. 25. The track begins with a voicemail from Selena's sister Gracie Teefey.
"Hi!" the 10-year-old says. "I love you, sissy. Never worry about boyfriends at all."
Selena has been friends with Taylor for more than a decade and last month attended one of her bestie's Eras tour concerts in Los Angeles with Gracie.
In July, the Only Murders in the Building actress and other several members of Taylor's famous "squad" attended the singer's Fourth of July party. Other guests included members of the band HAIM, who wrote on Instagram following the bash, "Single summer."
Meanwhile, Selena posted at the time, "Sometimes you need to be around empowering, kind and kick ass gals. I needed that."
Look back at Selena and Taylor's cutest BFF pics over the years below: