How sweet! Taylor Swift wasn't pictured in any of the birthday celebration images that Selena Gomez Instagrammed last night, but that doesn't mean she wasn't around to wish her bestie a happy 21st!
Taylor took to Twitter to post this picture today, complete with a heartfelt message that read, "Happy 21st birthday to my friend, and the closest thing I've ever had to a sister, @selenagomez!"
Aww, we knew they were super close, but it's so cool that Taylor thinks of Selena as a sister!
What do you think of Taylor's message? Leave a comment below to wish Selena a happy birthday too!