Only once in my life has something been up my ass. I was on holiday 10 years ago in St Barts, and my friends had just rolled a really big joint of weed in a bar. The bar was raided by cops who informed us they were doing a drugs raid and would check everything bar an internal body search. Drunkenly we decided as I had the biggest ass, we would roll several papers around the joint and I would take care of it till later.
Obviously my body temp soon degraded the paper wraps and I was heavenly stoned for about 4 days. Moral of the story--- what can seem as a good idea of an insertion at the time is not always necessarily so. 10 years later at drunken get togethers, they never let me forget that night.
Personally, I think it was the best Anal experience I have ever had xx