I just found a new fetish on the internet, I didn't think there is anything left to discover

Belly inflation, pumping your ass full of water filling up your inner tunnels till your belly starts to stretch and inflate.

Someone on quara posted a whole detailed essay on how to do this including yoga positions to help the water move around tight corners inside.
They even said you can stuff your self with loads of uncooked rice and then water so the rice absorb the water and your belly expand even more.

I can be an adventurous kinky freak but this too much for me