Stuffing

My gf graciously lets me stuff her sometimes, but doesn't want to gain weight.

We've had some success with smoothies blended with fruits and heavy cream. Makes her nice and big

But I was hoping to get some insight from others. How would one go about making themselves as bloated possible without gaining weight (or only a bit)?

Watermelon. My ex was similar but eating a whole personal watermelon made him nice and bloated. You want to be careful with straight water, there are risks of too much water in too short a period of time, but then again this whole fetish has a lot of risks. If you want to do just fluids I'd suggest something to balance the electrolytes so a low cal Gatorade. Otherwise smoothies with a non dairy base would probably be really good for your situation

I love the term 'personal watermelon,' haha.

Did one watermelon by itself get you the results you wanted?

Vegetables like cucumbers are also a good pick for this as they are mostly empty bulk.

Seriously, 2000 calories worth of cucumbers weigh 40 lbs.

I mean, you could just go the inflation route. Just hold your breath and pump air into your mouth, and it goes into your stomach. Zero calories. Buuut it can lead to pretty significant cramping if you go too fast.

Like with a bike pump? Or do you mean just swallowing the air? I'm trying to do it right now but it doesn't feel like I'm swallowing anything.

Bike pump works (go s l o w ) or a hand pump of some kind

Just skip your meals and eat the entire day's worth in one sitting. Then top off by chugging water. Also make sure to stop before the point where she might start feeling queasy (eat til you can't eat, then chug until you can't chug).