"What about a girl with really big boobs bouncing up and down on a pogo stick?"
I don't know, it's just not my scene, baby. Consider me OnlyFans on tranquilisers if you must, but I get much of my joy from imagining how huge breasts simply impact day-to-day life. The larger they get, the more they force improvisation and adaptation; from the clothes that are worn, to their stance or their gait. How they interact with objects around them, or with other people. It's fascinating. The challenges, the nuances, the pace. Two fleshy lumps can change the entire life of a person in more ways than you can imagine.
Even something as simple and mundane as hanging out the washing takes on a whole new challenge, when you think about it. The stretching, the counterbalancing of those two weighty titans. The deformation of the bra as the load changes, the gentle slosh and redistribution of flesh behind those soft capacious cups. Honestly, you can keep your pogo sticks.
Then there is always the impressive sight of a well-stocked washing line, adorned with the occasional over-size item of lingerie, just hinting at what the wearer might be blessed with. That alone is enough to spark the imagination.
As for a stronger washing line - you'd genuinely be amazed at the weight of a substantial bra! She might need that upgrade sooner, rather than later...