Used in some circles, mainly among stoners as The act of clumsily holding things between your thighs in close proximity to your crotch and trying not to drop them, while both you're hands are pre-occupied, usually with a bong and a lighter or a bag of Tostitos. This is fairly common when ones too high to understand that maybe the table next to them or even simply the floor is a more logical means of security for breakable items. When ones too stoned to remember that they're crotch-sheltering anything at all, or that they even put anything between their legs in the first place, this may result in something either crushing or dropping. That is how you break a bong. OR it can be used to call out someone either hogging the bong and not using it, or a bag of chips without eating it, while holding these things between their thighs.
Person 1: *finished bong hit* "person 2, I have the munchies, toss me the chips"
Person 2: *tosses person 1 the chips*
Person 1: *starts muching away on the chips and places bong in between legs without using it*
Person 2: "person 1, I want a hit where's the bong?"
Person 1: "I don't know" *too stoned obviously at this point* *spends 20 minutes looking around the room for the bong*
Person 2:"you idiot, youre crotch-sheltering it!"