For most Americans, 21 is a milestone birthday.
But for Jeremiah and Jedidiah Duggar -- both of whom reached legal drinking age this week -- very little will change in their rigidly structured lives.
The twins celebrated their birthday on December 30, but they did not mark the occasion with a toast.
You see, just like premarital front-hugging, alcohol is strictly forbidden in the Duggar household.
As In Touch Weekly points out, some of the older Duggar women have confessed to experimenting with booze in their youth, but drinking is severely frowned upon by the family's stern patriarch.
Fans thought Jed and Jer might be given a bit more leeway, as one of them no longer lives under Jim Bob's roof, but if anything, it looks like recent developments have encouraged JB to exercise even stricter control over his adult children.
As you may have heard, Jedidiah Duggar is running for office.
He's seeking a seat in the Arkansas State House of Representatives and has relocated to the district in which he hopes to be elected.
That means he's unmarried, but no longer living in the compound, an unheard-of state of affairs in the Duggar family.
At first, this was taken as a sign that the famously-strict Jim Bob had decided to lighten up a bit.
But it seems that JB has figured out a way to keep a close eye on Jed while also giving the man enough freedom to pursue his political ambitions.
For one thing, Jed reportedly resides in a house that's owned by Jim Bob.
JB is big into flipping real estate, and he owns properties all over the state.
Insiders claim that when Jed decided to run for office, finding him a home was as simple as taking one of those properties off the market and handing Jed the keys.
It was an uncharacteristically cool move from Jim Bob, but it came with strings attached.
For starters, the Duggars live in fear of what can happen when a person spends time alone.
It might sound insane -- and frankly, it is -- but Jim Bob and Michelle's children are almost always in the company of family, and Jed is no exception.
Sources close to the family say Jed almost never spends the night alone, as his brothers are constant visitors at "his" new home.
It's crucial, of course, that the sibling baby sitters are brothers, not sisters, as Duggar men are forbidden to be alone with female family members other than their mother.
It's unclear what Jim Bob fears might happen, but the Josh Duggar sex scandals are likely at the forefront of his mind.
Of course, one unintentional consequence of these precautions is that they remind the public of the skeletons in the Duggars' closet.
Another ramification is the effect that all of these rules might have on voters' perception of Jed.
After all, if his father can't trust him to live alone, how can the people of Arkansas trust him to represent their interests?