Bring an autoclicker.

It's an idler in the vein of, like, AdVenture Capitalist (rather than something more active), where you don't really do any clicking, you just buy stuff to make more money. In this case, you buy food which adds weight to the dragoness and increases your passive income.

The game's got a lot of issues big and small, though the belly's nice. Not a whole lot to say here, it's the usual stuff with a lot of "no-name" idle games, where nothing synergizes, progression stinks, automation is too slow, there's no optional content to hunt for, whatever.
The game tries to pad the play time a little bit by having you manage her stomach pressure, rubbing her belly when the bottom meter is getting too full. There's also a burp meter, but I don't know what that does.
Another big issue is that each food's cap is 200lbs (5 foods, total 1000lbs). Sure, that's 40 clicks for the biggest food, but the smallest means you're looking at clicking a LOT of times for the first couple foods, I'm talking like thousands of clicks, and you unlock the autoclickers towards the end of the game, AND they're slow.

Really the only good parts of the game is that her belly gets huge, and that the game's short enough to not be too grating or boring.

Hoping the dev regularly updates this for a while.