Dumb teens were at their dumbest back in the 1980s, that glorious era when nothing could stop hapless young horndogs from heading into the woods in search of kicks. Neither rain nor sleet nor gloom of night (nor psycho slashers with serious summer-camp trauma) could stop America’s hormonal young’uns from going where they shouldn’t and getting themselves gouged, gutted, and snicker-snacked for our viewing pleasure. Among the most pleasurable of the era’s abstinence-only educational flicks was the eye-popping, teen-chopping Friday the 13th Part III. Released on its namesake unlucky day in 1982, III finds crazy Jason Voorhees donning his hockey mask for the very first time. Add a few biker thugs, a hippie or two, a machete to the crotch, and a death by harpoon, and you’ve got classic splattertainment that will teach you to keep it in your pants, mister. The film shows at 10 p.m. and midnight at the AFI Silver Theatre and Cultural Center, 8633 Colesville Road, Silver Spring. $9.75. (301) 495-6700.