Sydney lived all of her life regretting one single action she made as a teenager. When's she's given the chance to make amends, she doesn't hesitate.

Dorothea, a regular sized girl, finds out that she just to be real tall for her age, until after a medical treatment her growth stopped and stayed 'normal sized'. After this discovery it is her biggest wish to reach the size, she 'should' have reached ...

It happened suddenly one day.  A being calling itself Sancus announced to the world that he had had enough of human deceit and dishonesty in the commitments and contracts they themselves enter into.  The so-called God of Contracts claimed that for those who wished to invoke his power, they need only write an agreement in his name and what was agreed upon in the document would be enforced by his power.
There were, however, several conditions for his power to be invoked.  Chief among the conditions are that no parties involved in the contract may be tricked into signing and that one cannot offer services or goods that do not belong to them.  These contracts need not be formal, dense documents to be overseen by Sancus, even an informal written agreement on a napkin will carry the weight his power so long as it is written in his name.
Through Sancus' power, corruption in society plummeted and everyone was using the fair ruling of the God of Contract's authority to conduct business on all levels.

A new invention allows Brobdingnags to grow Lilliputians to brobi size as part of arranged romances/partnerships. However, even with the new found size parity; it's a different kind of relationship when you have tiny in-laws. 

I try to explain the Giantess Fetish.

A series of one-shot stories where people start to slowly change size for various reasons and reality starts to alter around them. The world is rewritten to accept that. You were always this size, right?

A wife has a surprise for their husband after he is gone for a long business trip. He is about to take another trip, but this is strictly for pleasure.

Thomas finds himself in possesion of software than can alter reality, but whatever plans he may have had are quickly sidetracked by his little sister's desires. 

Marlin realizes that his dominance and dignity has become vulnerable as reality shifts, slowly shrinking him down in size, while his wife Aava gains size on him. As this change happens, the world around him shifts as if this change has never happened, and this was always the case, and only he realizes that a shift occured. He is constantly humiliated as reality slowly shifts to let his wife overpower hi and completely engulf him.

Slow shrinking story.