When it was announced earlier this month that the Hensel Twins, Abby & Brittany, had been given their own TLC series (premiering tonight) people who watch TV all the time were like, "FINALLY" and people who occasionally make time for other pursuits were like, "WHAT IS HAPPENING?"

This primer will answer some basic questions about conjoined twins Abby & Brittany and, in so doing, inspire you to come up with many, many more of your own.

Who are Abby and Brittany?
Abigail "Abby" Hensel and Brittany "Brittany" Hensel are 22-year-old conjoined twins from Minnesota. In the language of TV specials, they are "Joined for Life," "Twins Who Share a Body," or maybe 2 Girls 2 Cups 1 Body. The girls are best known from a series of documentary specials—one shot when they were 11, one shot when they were 16—that aired on the Discovery Channel and TLC, and are still re-run pretty frequently, especially during the dead zone between Christmas and New Years, when people have run out of things to say to their families.

The girls' new series, Abby and Brittany, will debut on TLC on Tuesday, August 28 at 10 p.m. (right after the season premiere of reality TV Duggarnaut 19 Kids and Counting). The show will follow the twins as they graduate from college (Bethel University in St. Paul), search for jobs, and travel across Europe. And, more importantly, as they have two heads and one body.

Yeah, I'm seeing a lot of heads here. How are they conjoined?
Abby and Brittany each have their own head, spine, heart, set of lungs, gallbladder, small intestine, and stomach. In broad terms, most everything else is shared. They have one wide ribcage two arms, two legs, two breasts, one bladder, one pelvis, and one set of reproductive organs. They were born with a third "rudimentary" arm protruding from their back, but this was surgically removed when they were very young, meaning it cannot appear as a straight-talking minor character in the series.

How… how?
Abby controls the right side of the twins' shared body while Brittany controls the left. One girl cannot sense touching on the other girl's "side." Each twin manipulates one arm and one leg. They're incredibly well coordinated with this set-up, able to walk with a smooth gait, dribble a basketball, and even ride a bike. The really mesmerizing thing is watching them type on a computer, as both girls' hands fly over the keys (millennials, ugh), but there's no verbal discussion of what they're writing.

What's so interesting about them?
Hi, are you a conjoined twin? What isn't interesting about this? Conjoined twins are incredibly rare, occurring once every 200,000 live births, according to the University of Maryland Medical Center. 40 to 60 percent of them arrive stillborn; about 35 percent survive only one day. The overall survival rate of conjoined twins is between 5 and 25 percent. Most of us will probably never meet conjoined twins.

(Interestingly, female twins have a much higher rate of live birth and survival than male twins. Approximately 70 percent of all conjoined twins are girls.)

The aspect of Abby and Brittany's story that is even more singularly compelling is that, unlike the dozens of TLC medical documentaries that take place in far flung regions of the world where access to modern medical care can be scarce at best, the Hensel sisters are, apart from that conjoined twin thing, archetypal Midwestern girls. They wears leggings, they flat-iron their hair, they back-sass their parents in the morning — they're just like us.

Do they have sex?
There is some debate about this among the members of the Gawker editorial staff, none of whom have had sex with Abby and Brittany. A rumor circulated in 2009 that Brittany was engaged, though the source of this seems to be an announcement on XM radio that was never broadcast anywhere else. The promo for their new show doesn't mention any love interests, which probably indicates that there are none, since that would be something to play up. Abby and Brittany have said they hope one day to marry and have children.

Do conjoined twins do that?
Sometimes. The world's most famous conjoined twins, Chang and Eng Bunker (born in Thailand in the 19th century — the inspiration for the term "Siamese twins"), married and had children with two sisters. Originally, the couples shared one home with one giant bed, but eventually the wives opted to live in separate houses, and the brothers split their time between two residences. Earlier this year in Wisconsin, a conjoined twin who was separated from her sister at birth gave birth to her own healthy baby. However, every set of conjoined twins is different. None of the aforementioned twins shared sexual organs, as Abby and Brittany do.

What might it look like if Abby and Brittany gave someone a blowjob?
It might look like this (NSFW) Photoshopped picture that made the rounds on the Internet a couple years ago.

Can they drive?
They can. Much of their sixteenth birthday special focused on their driving test. Abby, the louder, bossier sister who likes driving faster, operates the pedals and gearshift. Brittany, the dreamier, more easygoing twin is relegated to more boring jobs: blinker and lights. Both girls steer. They had to take their test twice – once for each girl (which, frankly seems a little silly, considering the breakdown of roles) and each has her own driver's license.

Are they Geminis?
No, they are Pisces (March 7). This means they are idealists who are in touch with their emotions. Their birthstone is aquamarine.

Are they di-vas?
Even though the girls would ostensibly like to generate interest in their upcoming TLC show, when we asked if they (or someone from the show) might be available for a Q&A, their PR lady responded, "They aren't doing any press." So, yes, they are di-vas.

Can we refer to them as Siamese twins?
Much like it is nowadays considered impolite to invite an Indian giver over for Oriental food so you can make racist remarks about the goddamned lazy Swedes, so is it considered rude to refer to conjoined twins as Siamese.

But what about We Are Si-a-mese, If You Please?
Listen, we all love the We Are Si-a-mese song. But watch this cartoon. It's way more offensive than you remember, right?

So basically the show exists so we can oggle these girls in private? I thought TLC was supposed to be The Learning Channel. What the hell happened?
This is one of the stalest observations a person can make on the internet but, since you brought it up, TLC's (alleged) downward spiral began with the program Jon and Kate Plus 8, a show about a problem child named Maddie, her seven siblings, and her parents. From there, we moved to 19 Kids & Counting, Toddlers & Tiaras, and now the apex of observational learning Here Comes Honey Boo-Boo. The criticism that TLC isn't doing enough to educate its viewers is a weak one, because, if you really wanted to explore the world of science, you wouldn't rely on the folks who brought you A Wedding Story to do it. Anyway, look at all you've learned about conjoined twins so far today.

What happens if one of the girls doesn't want to have sex with a man but the other one does — is that rape? Do they have to buy separate tickets if they see a 3-D movie, because they require one seat but two sets of glasses? What if Abby had failed her driving test but Brittany had passed it? What if one of them is sleepy and the other one is wide awake? Since they have two stomachs but one bladder do they have to pee all the time? What if one had graduated high school but the other had failed all her classes? What happens if they have to throw up?

Who knows? They aren't doing press. But now you've uncovered the real fun of Abby & Brittany: coming up with an endless list of questions you will never ask them in real life, because it would be rude.

[People // University of Maryland Medical Center]