@Olo
Personally, I imagine it going in one of two ways:
First, a singular focus on the scientist experimenting on the giant, coming to realize that a powerful man bound up in chains is, in fact, hot to her. And that he’s really, really big, and that’s hot. And even between his legs, he’s bigger than her. And she has a shock prod, and it’s actually kind of fun to use it, and it’s hard to feel guilty about it considering how little reaction he has to that.
Fun times insue, with the scientist exploring her new found kinks with her somewhat willing partner. Story eventually ends with giant breaking out in a, ‘oh shit’, kind of way.
The other would be flipping perspectives between the giant and the scientist: the scientist is very into the whole giant thing as well, but she’s also forced into experimenting on him by her superiors and so she’s very conflicted morally about what she’s doing. Still, she ends up striking a relationship with her test subject.
Meanwhile, the giant is planning his escape; he’s been growing stronger steadily, and hiding that, and is at a point where he could escape his chains easily enough, but isn’t sure about the facility itself, so he’s biding his time as he gets stronger and stronger. He’s been acting compliant even as the various things they use to hold him back stopped working as well, and is faking unconsciousness when he’s drugged and the like, because he doesn’t want them to up their preparations about him before he’s ready.
He absolutely plans to flatten everyone in a lab coat he can find on his way out.
Then this one scientist tries to make things better for him and apologizes and he is Confused™. Fully planning for the scientist to find out he’s not nearly as bound as they thought, him almost kill her to hid that knowledge, but decided not to out of trust, while she returns that trust by not ratting him out, even as it sends her into mental spirals.
Basiclly, the first one is a short story, the second is the much longer version.