There are so many wonderful mysteries left in the world. In an era when so much can be laid bare with just a few keystrokes, it’s comforting, somehow, to know that there is much we don’t fully understand. Not just the odd bits here and there, but some fairly big things, like the true nature of gravity, or why exactly we need to sleep.

But if those questions are usually left to the big brains among us, there is an equally long-lasting mystery that has befuddled the human mind for millennia: sex. There’s a reason the “world’s oldest profession” isn’t astronomy. Whether we’re having it with others or just with ourselves, all that warm tingling can lead to a state of confusion peppered with questions like “Am I in love?” and “Is it supposed to bend that way?”

The drive to answer some of those burning questions led to an eruption of sex-ed videos in the last few decades. Some of the weirdest of them have been brought together this week in The Wonderful World of Boning: Sex Ed With a Sense of Humor, a show coming in for a one-night stand at the Hadley arts and exhibition space Flying Object. Getting underway at 8 p.m. on Thursday, Dec. 11, the traveling show features films like Seriously Fresh, which pairs lessons about HIV with ’90s lingo; You, Your Body, and Puberty (“a guide to the weird experience of adolescence”); and the 1981 genre classic A Family Talks About Sex (“How many times do I have to have gay sex before I’m considered gay?”).

Lending their wit to the proceedings are hosts Lux Alptraum and Tiara Francis. Alptraum’s career has set her up perfectly for a role as commentator: after stints as a sex-ed teacher to teenagers (where she first began collecting some of the clips in the show) and editor/publisher of sex blog Fleshbot, she’s a writer/consultant who recently covered a celebrity photo hacking scandal for al Jazeera America. Francis is an actor and comedian who honed her improv chops studying with The Upright Citizens Brigade and the women-of-color troupe Affirmative Action.

Also this week: Cinemark Theaters is bringing in a few special shows featuring films old and new alike. First up is a Sunday big-screen showing (with a Wednesday encore) of the holiday classic White Christmas, starring Bing Crosby and Danny Kaye as World War II veterans and nightclub entertainers Bob Wallace and Phil Davis. The plot — in which the two fall for a singing sisters act played by Rosemary Clooney and Vera-Ellen while scheming to save a failing inn — is mostly a framework on which Paramount could hang its collection of Irving Berlin tunes. But what tunes! The title song and “Blue Skies” are perhaps the best known, but for my money, it’s always Clooney’s rendition of “Love, You Didn’t Do Right By Me” that steals the show.

On Monday, Dec. 15, the theater presents an eight-hour Middle Earth extravaganza when it shows the full trilogy of Peter Jackson’s The Hobbit series all in one sitting. The Battle of the Five Armies is the final installment in the series, which stars Martin Freeman as hobbit Bilbo Baggins (and which reunites him with his Sherlock co-star Benedict Cumberbatch, here playing the dragon Smaug). For fans, the marathon is an early Christmas gift: to see it on its own, you’ll have to wait until Dec. 17. Of course, by the time you sit through the full trilogy, you may well feel like it’s been two days anyway. If you feel up to the challenge, the first film starts at 1 p.m.•

Jack Brown can be reached at cinemadope@gmail.com.