Bag of holding that has far more space than a standard bag, but it's because it's linked to a pair of magical implants in your breasts. Different thresholds of fullness correspond to larger and larger breast sizes.
Starting off at your 'natural' size before you go on an adventure, just the essentials in there, not taking up much room.
But then you manage to find a treasure hoard and as your companion fills the bag up, your tits swell larger and larger, your armour groaning as you try and take it off before it snaps (you've asked them to let you get undressed after a battle before, but they never give you the chance, the pervs)
Sure, at a certain point it does encumber you, but it's still way more than any of you could actually carry!
And... and so what if everyone stares when you come back to the trading town? It's convenient magic!
And you know that several of the store owners find you a lot more... persuasive... when you're all full of treasure like that.
One night, you're in the tavern, having sold off about half of your haul (still leaving you pretty well endowed) and you're hanging on the arm of some bard who's passing through, figuring out whose room you'll both retire to, when suddenly your tits MASSIVELY inflate, ripping open your tunic and spilling out over the bard's lap and onto the table.
Everyone gasps, and you're so embarrassed you feel flushed from your hairline to your absolutely ridiculous tits.
You yell for your companions, asking them who has the connected bag-- and that's when you discover that someone got pickpocketed while you were all carousing!
Thankfully, there's a homing spell built into the magic so you can't lose the bag, but you're not exactly super mobile right now... Until the bard casts a spell on you, or on your tits, really, which float up with the help of two large, spectral hands.
You can't see over your vision-blocking bust, so your companions tie a rope around your waist and you follow them out. You try and ignore everyone's gaze as you walk past, especially when you fail to hold in your moans when your tits grow even larger again.
By the time you track down the thief with your bag, your tits probably have more mass than the rest of you, and it's hard to think because they're so full and jiggly.
They've shoved an entire armoury's worth of merchandise inside your tits, as well as enough food and water rations for several months, gold and silver and platinum and whatever else their nimble fingers could grab.
You tell them that the fun's over, but they need to put everything back, but your companion cuts you off, telling you to hold on, that you should all consider this--
You've been the party's secondary melee fighter, supporting a trained warrior, and a wizard (the one who made you the magical breast augments in the first place), and the bard's still been trailing along keeping your tits afloat (and enjoying the sight if not the feel of groping them through the spell), and having someone who could disarm traps and locks and whatnot would be useful...
Plus. Well. All that loot is already stolen...
You try and object-- you didn't mind increasing your carrying capacity but this is a whole order of magnitude different! But they're not really listening to you, instead discussing logistics and how much more they could fit in before getting out of the town for a while.
The thief knows some fences a few cities over, so it should all be fine.
They end up using some of the gold to buy a caravan to haul you along in. By the time you get to the thief's promised fence and they start unloading your tits, you're just grateful enough to be able to move under your own power that you can't even scold them for it. It's been so long. And... and now you feel so small, and flat, and it's... it's weird.
Unsurprisingly, they don't need much convincing to head off on another dungeon crawl to search for loot...
You might not be as good for combat encounters these days, but you more than make up for it in utility and moral support for your party.
snowghoul
pixelskylines
dailybridgerton
tangentwithtanner
