Brad Pitt began dating Jennifer Aniston in 1998 and the pair were married from 2000 to 2005. Photo / Getty Images
Brad Pitt began dating Jennifer Aniston in 1998 and the pair were married from 2000 to 2005. Photo / Getty Images
From Reese Witherspoon to Brad Pitt, Friends has had some very famous faces show up during the 10 years the show aired. But a few other famous celebrities who didn't star on Friends joined the cast for the two-hour reunion episode.
Reese Witherspoon
Reese Witherspoon made her first Friends appearanceback in 2000 as Rachel's younger sister, Jill.
Reese Witherspoon only featured in two Friends episodes during the show's 6th season. Photo / Getty Images
She appeared on the reunion, blushing over the fact she was able to hear Matt Le Blanc say Joeys iconic line "How you doin'".
In an interview with Jennifer Aniston, Witherspoon told AP she was "too scared" to return to the iconic show.
Reese Witherspoon (@ReeseW) reveals that she was asked back to #Friends but declined. Unlike Jennifer Aniston, she did not enjoy performing in front of a live studio audience when she played Aniston’s sister on the show. pic.twitter.com/tdSpE3Eo7S
Guest star Tom Selleck best known for his role as private investigator Thomas Magnum came into the Friends fictional world in the second season playing the role of Richard Burke, Monica's older boyfriend.
Tom Selleck guest starred in 10 episodes of Friends. Photo / Getty Images
Selleck made a quick cameo during the first half of the reunion while the main characters were playing a quiz game. He was the mystery voice on a voicemail where the cast members had to figure out who he was.
Lisa Kudrow takes her position on the Central Perk couch to perform a rendition of Smelly Cat with a very special guest.
Lady Gaga!
Sitting down next to the actress, dressed in a striking pink and orange outfit Phoebe would have rocked, Gaga belts out the verses with her, with a gospel choir bursting through the door for backup vocals.
Bieber's role in the reunion special in particular set tongues wagging on social media, with many wondering why he was chosen over former guests of the show such as Paul Rudd.
Paul Rudd
One famous face which seemed to stick around was Phoebe Buffay's boyfriend turned husband Paul Rudd. Who is now also known for his role in the Marvel films Ant-Man.
Phoebe ties the knot with Mike in Friends. Photo / News Corp Australia
Rudd made his Friends debut as Phoebe Buffay's love interest on season nine.
