Get two very large trash bags and tape them together to make one large
It takes a little practice to get the ends taped just right.
Step 2: Fill them
inflate the bags with air (vacuum cleaner) and when it gets almost full but
not quite, I remove the air supply and tape over the hole.
Step 3: Hop on
Lube up your cock and get on top of the bags and begin humping.. When you
get close to cumming, you can puncture a small hole or maybe a few holes in
the bag and "ride" it down. Time it to cum just before you hit bottom.