Looking back, perhaps we should have known this day would come.
In retrospect, it seems obvious that Jill Duggar would eventually be the first of her many siblings to really rebel against Jim Bob Duggar.
The signs have been there for quite some time, and we're not just talking about the feud between Derick Dillard and Jim Bob.
Even before that spat began, Jill's actions made it clear that her true loyalty was not to her father, but to her husband -- and that she was intent on living the kind of life she imagined for herself, not the one Jim Bob laid out for her.
Sure, Jinger has rebelled against her overbearing upbringing by defying the Duggar dress code and moving to LA, but even she would never dream of teaming up with her defiant cousin to flip Jim Bob the bird on his birthday.
Okay, so Jill and Amy didn't literally give Jim Bob the finger, but this is a pretty big -- and pretty public -- eff you to the patriarch.
That's a photo of Jill, Amy, and their men at the wine and cigar bar owned by Amy's husband, Dillon King.
The photo -- which was posted on Amy's Instagram page -- was apparently snapped on Saturday ... which just happened to be Jim Bob's birthday.
Yes, Jill skipped Jim Bob's birthday bash to hang with her cousin Amy who has essentially been exiled from the rest of the family due to Jim Bob's disapproval.
Not only that, Jill hung out at an establishment that specialized in wine and cigars, two things Jim Bob disapporves of even more than he disapproves of Amy!
In case that wasn't evidence enough that Jill's not even pretending to care Jim Bob's opinion anymore, Amy's caption really drove the point home:
"Our new favorite word: Freedom!" she wrote, as first reported by The Ashley's Reality Roundup.
As you're probably aware, the Duggar kids have a long list of rules that they're expected to follow at all times.
As they've entered adulthood, some of them have been selective about which ones they'd like to continue abiding by (see Jinger's aforementioned disregard for the Duggar dress code).
But certain regulations are considered non-negotiable, and the family ban on vices such as booze and tobacco is one of them.
Perhaps that's why Derick delighted in confirming that he and his wife enjoyed a cocktail or 12 in the company of their new besties.
"Thanks for treating us! We had a great time! Good food, drinks, and company (not necessarily in that order ;)," Derick commented on Amy's post.
Now, we suppose it's possible that when he said "drinks," Derick was referring to something as innocent as a Diet Coke, but that winky face at the end seems to indicate otherwise.
(Also, can someone tell this guy to step up his emoji game? It's 2020, Der!)
“We had so much fun! Next time Brunch, drinks and the patio!” Amy replied to Derick's comment, seemingly confirming that the beverages he was referring to were of the adult variety.
On Twitter, Amy also confirmed that the "freedom" she referred to in her post was freedom from overbearing parents.
"Remember: you can't choose your family ..but you can choose your therapist!" she tweeted on the day that Jim Bob turned 55.
Several of Jill's siblings and in-laws, including Jessa, Joy-Anna, and Anna, took to Instagram to wish Jim Bob a happy birthday.
But we probably don't need to tell you that Jill and Amy did no such thing.
On Instagram, Michelle Duggar posted a pic from Jim Bob's birthday party, along with a lengthy tribute to the father of 19:
“We have had a wonderful day celebrating this amazing husband, dad, and grandpa!!” Michelle wrote.
“Happy birthday to the love of my life, Jim Bob! You are my best friend," she continued.
"I love laughing with you, praying with you, and doing life with you! Your heart to love and honor the Lord and follow the Bible as the ‘owner’s manual for life’ is something I treasure in you!"
Jim Bob hasn't responded publicly to the revelation that his second-eldest daughter is a fan of the devil's grape juice.
But you can bet he's not a fan of this new development -- and it's yet another sign that this rift within the Duggar clan won't be mended any time soon!