True, we're used to seeing Tay rub elbows with her famous friends and model besties, but she and Abigail have remained friends since before Taylor reached her meteoric level of success.
But getting back to that birthday party – Abigail celebrated her 25th with some of the most insane surprises, including partying it up with Paramore's Hayley Williams and a special appearance by the lead singer of her fave band, Dashboard Confessional. Taylor, Abigail and the party guests all got to sing "Hands Down" with Chris Carrabba!
You have to watch the videos Taylor posted to get the full effect of Abigail's utter shock and surprise - and check out the pics of her hanging with Hayley and Chris too. Taylor later tweeted: "@ChrisCarrabba, I'll never be able to thank you enough for showing up to surprise Abigail. Thank you for caring so much about your fans."
Well done, Taylor.