The history of cinema is boys photographing girls.The limit of the Willing Suspension of Disbelief for a given element is directly proportional to its sexiness. In other words, when things are sufficiently sexy, viewers will accept them, even when they are outright impossible, or just astronomically improbable. A Sister Trope to Sex Sells. Compare Rule of Funny, Rule of Cool.
A Super Trope to:
- Breast Expansion: In reality, breasts can't suddenly expand.
- Chain Mail Bikini: In reality, you should not fight in bikini-shaped armor, because it protects only some vital areas but not others.
- Clothing Damage: In reality, clothing does not degrade in a conveniently alluring fashion.
- Combat Stilettos: In reality, you cannot run and fight in stiletto heels.
- Custom Uniform of Sexy: In reality, each uniform is standard.
- Deus Sex Machina: In reality, sex is not magical.
- Exposed to the Elements: In reality, clothing inappropriate to the elements can prove harmful or fatal.
- Form-Fitting Wardrobe: In reality, a limit exists on how tight clothing can be (even when there is variance in material flexibility).
- Gainaxing: In reality, breasts do not bounce that much, especially if they're larger and heavier!
- Gendered Outfit: In reality, uniforms created for both genders consider practicality, rather than just showing as much skin as possible.
- Green-Skinned Space Babe: In reality, were aliens to exist, we (most likely) could not have sex with them.
- Hartman Hips: In reality, the human body only forms a slight pear shape.
- Hospital Hottie: In reality, hospital personnel dress for practicality.
- Hot Wind: In reality, wind does not appear just to make someone's hair and clothes move around seductively.
- Impossible Hourglass Figure: In reality, the human figure forms only a slight hourglass even in the most ideal figures.
- Intimate Healing: In real life, sex or sensual actions do not heal serious injuries.
- Latex Space Suit: In reality, space suits are bulky to protect the wearer. And the closest experimental suits require the wearer to pack putty or fluid-filled sacs around anything that would otherwise stick out (like breasts and groins).
- Most Common Superpower: In reality, were superheroines and villainesses to exist, they would not all have large breasts.
- Naughty Nuns: In reality, nuns are more chaste than most people.
- Naughty Nurse Outfit: In reality, nurses dress for practicality.
- Naughty Tentacles - In reality, were tentacles to become sentient, no reason would exist for sex with humans.
- Non-Mammal Mammaries: In reality, non-mammals don't have mammaries and even with mammals, they usually don't stick out like human breasts (not even primates).
- Orgasmic Combat: In reality, fighting does not sound like sex (and someone would have particular issues to get turned on by fighting in it).
- She-Fu: In reality, such techniques are highly impractical in combat.
- Spy Catsuit: In reality, people cannot wear skintight clothing while remaining mobile and stealthy (barring flexible clothing material).
- Stripperiffic: In reality, people cannot carry out jobs while wearing clothing unsuitable for the application.
- Suggestive Collision: In reality, when people collide, it's extremely unlikely that one person ends up pinned against the other person's sexy bits.
- Waif-Fu: In reality, slim women do not hit that hard.
- World of Buxom: In reality, breasts come in various sizes, even small.
...but in fiction, we accept the alternative, because it's sexy.