The Laws of Body Inflation

Law of Pneumatic Economy:  Compressed gasses are so cheap as to be practically free.  Thus various people and organizations who have no particular reason to keep tanks of compressed gas around do so just in case they're needed someday.

Law of Containment Durability:  Devices which are designed to contain or convey compressed gasses (tanks, hoses, pumps, etc) are made from highly durable materials and engineered to a level suitable for high-end aerospace applications.  As such, they will never fail even when under extreme stress and operating well outside of their design specifications.

Law of Excess Capacity: Because compressed gasses are free and the tanks are nigh indestructible, it's fairly routine for a vessel to contain a quantity of gas that's far greater than what's required for its intended purpose. Thus you'll often find a blimp's worth of helium in a tank used for filling party balloons.

Law of Pneumatic Control Fragility:  Knobs, valves, and other devices used for controlling the flow of compressed gasses are designed by the lowest bidder and and only manufactured on Fridays, between 4:30PM and 5:05PM, by disgruntled sweat shop workers.  They are of poor quality, quite frail, and will often fail when exposed to significant stress.  The stress that results from normal use will usually do it.

Murphy's Law of Pneumatic Control Fragility:  When a valve or pump fails, it will fail in the "on" position.

Law of Biogenic Buoyancy:  Any gas will become lighter once pumped to a person.  A beach ball filled with helium won't float away, but anyone who inhales a similar volume of helium will quickly become airborne.  Even ordinary air can provide lift if pumped into a person in sufficient quantity.

Law of Garment Elasticity: All clothing stretches to varying degrees.  A latex catsuit can be stretched to the size of a large zeppelin, while a chain mail bikini may only stretch a few feet before breaking.  Belts are the only exception; they will not stretch at all, and invariably cinch the inflating person's torso quite uncomfortably until removed.

Law of Garment Fastener Intransigence: Any device used to secure clothing (buttons, zippers, etc) will become impossible to operate once under tension.  The only way for an inflating person to get out of their clothing is to burst out of it.  Belts are the only exception; because belts don't stretch, the buckles remain undeformed and operational.

First Law of Mutual Feminine Attraction:  20% of women are lesbians.

Second Law of Mutual Feminine Attraction:  36% of women are bisexual.

Third Law of Mutual Feminine Attraction:  23% of women are straight, mostly, but still kinda into chicks and would totally make out with another girl under the right circumstances if she was really hot or inflated.

Fourth Law of Mutual Feminine Attraction:  21% of women are completely straight, but oh my God look at how huge I am this is so weird why am I so turned on and it feels pretty good when you touch me like that and it's not like I can stop you anyway so I guess you can keep going just don't tell anyone about this.

Fifth Law of Mutual Feminine Attraction:  There are seventeen women in the world who are not at all attracted to other women, and would only have sex with another woman if forced to by the threat of imminent bodily harm.  Currently all seventeen are being held prisoner at gunpoint by psychotic lesbian inflationists.

First Law of Mutual Masculine Attraction:  In every recorded case in history, sexual contact between two men has resulted in one of the men inflating and exploding.

Second Law of Mutual Masculine Attraction: As a consequence of the First Law, homosexual men are so rare that their existence is still considered by many to be a myth.

Law of Pneumatofacient Undetectability: Despite being potentially dangerous, all drugs and chemicals that cause inflation are designed in such a way that dramatically increases the chances of them being inadvertently consumed.
     First Corollary: 90% of chemicals that cause inflation are similar to iocaine powder: odorless, colorless, and dissolve instantly in liquid.
     Second Corollary: 10% of the chemicals will only impart a mild flavor that will be immediately dismissed by the person consuming it.

Law of Pharmaceutical Disclosure:  All drugs which could potentially cause inflation are labeled with detailed guidelines for dosages and descriptions of potentially adverse interactions and side effects.  "Exploding" is usually one of the possible side effects.

Law of Contraindicatory Indifference:  Most people never read the warnings on inflation drugs.

Law of Memory Transience:  Most people who do read the warnings on inflation drugs will have no recollection of doing so.  Thus when side effects occur, they will come as a complete surprise.

Law of Perverse Subliminal Suggestion:  Although most people will not consciously recall any contraindications listed on drug labels, such warnings will act as a subliminal suggestions.  So if a label says "DO NOT TAKE MORE THAN ONE PILL -- DO NOT TAKE WITH CARBONATED BEVERAGES",  then the user will take two pills and wash them down with a soda.

Law of Presumed Contraindication Flexibility:  Those few people who read the instructions for inflation drugs and remember them will still treat dosage guidelines as suggestions, no matter how sternly they're worded.

Law of Pneumatically Induced Recollection:  Inflation enhances memory recall.  Thus someone who completely forgot about the instructions prior to inflating will often have an "Ahah!" moment of remembering them shortly before exploding.

First Law of Pneumatic Aeronautical Failure:  If a person inflates on an airplane, then the plane will experience a loss of cabin pressure at cruising altitude.  The resulting decrease in pressure will cause further inflation.

Second Law of Pneumatic Aeronautical Failure:  After a plane loses cabin pressure, the oxygen mask used by an inflated person will malfunction.  This will result in excessive oxygen flow and further inflation.

Law of Barometric Magnification:  A drop in atmospheric pressure will cause a disproportionately large change in the volume of gas inside a person.  Thus a ten percent decrease in external pressure will cause an inflated person to double in size.

Law of Terminal Decompression:  Even if a person has already endured substantial inflation through other means without problems or complications, any further inflation that is brought about by a drop in external air pressure will ultimately result in that person exploding.

Law of Mass Non-Conservation:  A person inflates, his mass decreases.  An inflated person, once completely round, will have so little mass that he may be easily picked up and tossed around like a beach ball.  By the time an inflated person pops, he will have almost no mass left.  If there are any remnants at all, they will be a few small shreds similar to those left by a popped balloon.

Law of Pneumatic Pulchritude:  A woman's attractiveness is proportional to the volume of gas she contains.  Ever notice how much attention a woman can get by taking a deep breath?  Body inflation extends this effect.

Law of Pneumatic Conflict Resolution:  It's perfectly reasonable for two people to settle a dispute by inflating until one of them bursts.
     First Corollary:  Due to the Law of Pneumatic Pulchritude, it is quite common for two women to engage in competitive inflation in order to establish who is more attractive.
     Second Corollary:  A man will only engage in competitive inflation if he's challenged by an attractive woman who's previously humiliated him.
Third Corollary:  While a man will never enter an inflation contest with another man, he may challenge himself to see how large he can inflate.  This invariably ends with him bursting.

Law of Mutually Assured Pneumatic Destruction:  Any contest where two people compete to see who can inflate more will usually result in both competitors popping.