Justin Theroux Just Wished Ex-Wife Jennifer Aniston Happy Birthday On Instagram, And I Have Questions

Jennifer Aniston turned 51 on Tuesday, February 11 (I can't believe it either), and got tons of love and shoutouts on Instagramwhich she just recently joined from her fans and famous friends. One of the most notable HBD posts came from Jennifer's ex-husband, Justin Theroux, who shared a picture of The Morning Show star and some sweet words on his Instagram Stories.

"grabbing 2020 & another year just like..." he captioned a fierce black and white photo of Jennifer, along with "happy Birthday, B ."

While it's not the first time he's given her a birthday shout-out on the social media platform ( Justin also did so last year ), it's also not the first time he's called Jenniferwhose name starts with the letter J"B." So... what the heck does that "B" stand for? Babe? Baby? Beau? Boo? Maybe even (hold your cringes) Boo Thang? Bestie?

E! News tried to decipher the meaning of it, noting, "There is no telling what exactly the Leftovers star meant by 'B' considering that's neither her first or last initial, and her middle name is Joanna. Must mean it's a sweetand possibly secretnickname Justin has for his former love." (Awwww, but I still need to know!)

Aside from that burning question, Justin's bday post raises some others: Where did this picture of Jennifer come from? What was she saying at the time? What is that stone tiger doing in the corner? And how the heck do Jens arms always look so freakin' toned???

Justin likely won't be offering up answers anytime soon, however, he has commented on Jen's Instagram posts previously. After the Friends alum's first IG posta photo of herself and the rest of the cast including Lisa Kudrow, Courteney Cox , Matthew Perry, Matt LeBlanc, and David Schwimmerhe chimed in with "woot woot" and "#first."

While the exes keep sharing the social media love, I'll be over here trying to break Justin's code... any ideas?!