"Happy Birthday to this fierce Woman. Fiercely loving. Fiercely kind. ....and fiercely funny. ❤️ you B," the 49-year-old actor captioned a pic of his former flame with toned arms holding up a pair of horns.
Aniston and Theroux announced they were parting ways just days after her 49th birthday in 2018. In October of that year, a source told ET that both were doing well following the breakup.
"Since they split, her friends believe their plan to move forward in life without one another was the best decision for both of them," the source said at the time. "Neither of them is pining for each other but instead, finding themselves again."
Cut to 2020, Aniston delighted fans when she reconnected with her first ex-husband, Brad Pitt, and was photographed with him for the first time at a public event since their breakup in 2005.
Here's a look at Pitt and Aniston's reunion at the SAG Awards.