Okay, so I'm looking for some input/ideas...
I've recently divulged this interest/kink to my partner (body inflation is my actual taste), as potentially weird as it sounds to people outside of the community. I think my partner would be up for playing in this realm to indulge me.
First and simplest thought is, a beachball under their shirt, being inflated slowly by an aquarium pump while we play.
Any thoughts or past experiences from the community on other things we could do? I don't want to go over the top, especially to start. As harmless as this interest is, for non-inflation people this could be a little "out there". Obviously, sharing this with them is a really big trust thing, and I don't want to damage that.
Hm... well, I don't have a girl, so I can't really tell you two how to bang each other, but what I am is a neuroscience major in college, so from maybe start by showing them some SFW art or short stories to test the water? Maybe watch all of Charlie and the Chocolate Factory, and explain how the Violet scene is what started a lot of our fetishes, to give her an idea of things. Don't jump into NSFW stuff, let her do that.
The only other advice I could give could be considered a very minor form of mental manipulation/conditioning, though, and I don't just hand that info out to anyone without knowing I can trust them. Experiments of that kimd on humans is unethical, so unless she asks you to help her get a bit more involved in this link, my lips are sealed.