Do you keep inflating to the same size everytime and very slowly getting bigger each time, or do you have other methods?
im not sure how it works for other methods of inflation but i know if works when i inflate with a bike pump. I start off by slowly inflating myself like normal, then over a long period of time slowly keep pumping myself up (it probably works best with a bike pump because you can really controll how much air you're pumping in) i feel like this stretches me, allowing me to get much bigger than i did the time before.
yes its time consuming, but i find it works really well and im now able to inflate HUGE compared to when i started :D
I seemed to only manage a few pump's bug try the odd extra when i inflate :)