I got a dare for you
Get a fizzy drinks can and put it in a bucket of ice. Then insert 3 peices of ice into ur ass then the can and then 4 peices of ice. Put as much ice as you can so it not painful and just under your limit. Then fit in a pair of panties in to stop it all coming out. Then suck the panties dry. Keep the can in your ass for 5 mins or longer
Let me know how long u can keep it in
If this is to hard then get one of those small cans what cost like 25p from tesco or somet or chop a banana into a managable size strip and freeze it