In real life, same-size human societies have had a very poor record of protecting the weak from abuse by the strong. Sadly, I see little reason why this would be any different in a mixed-size society.
World-building is hard, and any mixed-sized society with any sort of history (ie, the differing sizes weren’t introduced to each other yesterday) is going to have to account for lots of things, starting with simple infrastructure (giants navigating city streets, tinies navigating furniture) to logistics (how do giants get fed and where does their waste go?) all the way up to legal rights and duties and political/economic relations.
The very first thing that needs to be addressed is whether giants and tinies are separate civilizations/species that evolved individually and then later came into contact or if everyone used to be the same size and then Something Happened (magic, disease, technology, mutation, etc) that changed the size of a subset of the population. In the former case, it’s going to be more of an alien first-contact situation where both sizes have to determine how to regard the other and if they extend the same rights and privileges to any “co-habitants.” In the latter case, the social discussion gets more complex as everyone makes their own decision how to treat the people of the new, different size. It gets even spicier if the size-change isn’t a one-off event but You Could Be Next. Of course, the relatively larger people will have some advantages, but if the relatively smaller people have better tech or magic or whatever, the giants could end up ostracized or even persecuted.
As far as modern technology goes, once there are surveillance satellites or even airplanes there’s no place on the Earth’s surface for a giant society to hide, and I can’t see our current civilization tolerating even a single giant without either nuking them or hounding them to death with paparazzi (or, probably, both). Tinies might be able to hide for a while, but eventually one will be captured and then everyone will want one for their Instagram. My first true giant story (Accommodations) was deliberately set in a pre-industrial world to give giants some privacy.
I think any size encounter is vastly improved when the above issues are given due consideration. Is the size difference novel, or is it routine? Have the characters ever encountered someone of a different size before, and if so, was it a good experience or poor? Do they have prejudices or phobias about people of a different size? And, of course, has anyone ever thought about or tried having sex with someone of a different size?
At first, societies will try to extend existing arrangements to the new situation. If previously-“normal” people are somehow shrunk (by a disease, for example), they might be considered disabled and accommodations mandated by the government. Suddenly large people present a hazard to those around them, and the local community might try to use permits or zoning laws to restrict giants to certain areas. Relatively small people might also be required to remain in certain areas or to wear warning lights and sounds to alert giants to their presence. Tinies might have assigned guardians with certain custody privileges. Can tinies give meaningful consent? Are giants obliged to pay for any damage they cause? Can giants and tinies be co-workers?
For my first size fantasy story, I decided I wanted a) giants and tinies to live mostly in physically separate spaces, and b) I wanted the giants to be the “normies” and tinies to be shrunken (former normies). Both of these elements were crucial for what I had planned for the main relationship between different-size characters. I wanted the first element because it’s very difficult to imagine tinies living with security and dignity among giants, and I wanted my tiny characters to come from some sort of recognizable society of their own rather than living inside walls and under floorboards. I also wanted the giants and tinies to live separately because I wanted the encounter between them to be somewhat novel to my characters so there would be a good reason for the vivid descriptions that I expected my readers to want.
The reason that I wanted my tinies to be artificially shrunken (by technology, in this case) is that wanted to have giants who thought of themselves as “normal” and considered tinies as inferior, but I also wanted them all to be the same species. When the tinies are aliens or fairies or Borrowers, it’s that much more difficult for them to plausibly arrive at the sexytimes we’re all after. With a tiny society physically segregated from everyone else, the giants can think or joke about having sex with tinies, but no one you know has actually done it. That’s the novel temptation I wanted to achieve.
So I came up with what I call the Big Sky universe. It’s set in the near-future, with climate change making less of the planet habitable, after the discovery of way to extract vast amounts of energy from physical objects by reducing them in size, with animal organisms yielding the greatest amount. By shrinking humans, clean energy is generated while reducing our strain on the planet. It’s first applied to prisoners, of course, but our savage civilization eventually extendeds it to refugees and anyone seeking government assistance. “For their safety,” shrunken people are confined to underground warrens, where the quality of life is inevitably worse than the full-size people still dwelling in Big Sky.
If you want to read it, here it is: A Little Trouble in Big Sky (Warning: It’s almost entirely F/m, but there are few brief SW scenes at the end.)
For an M/f example, my (much shorter) story License posits a world where tinies are treated as little better than vermin.
Again, world-building is hard but rewarding.
Too bad Camila wasn’t watching; it might have helped her “get it.” jk 
