Docking

It's a lot of fun, actually. I don't think I would take docking for a main course, but it's a great appetizer...or dessert. And it's something you can do in a few different ways. As MarkLondon pointed out, you can lube things up and swirl them around in there. You can also get a motion going so it's like you're fucking each others' foreskin. Cumming that way is actually pretty spectacular, especially if you can time it so you cum together.
 
As a cut male I was introduced to docking by a hot guy with a really loose but not overly long foreskin. He wanted me feel what it would be like to be uncut as I had told him I wished my parents had not gotten me circumcised. I got incredibly turned on knowing that my head was going to have foreskin over it.The experience ended after jacking our cocks while docked with him stretching and holding his foreskin over the head of my cock while we both blew our loads inside his foreskin. This was about 30 years ago.
I don't consider it to be a fetish for me but do enjoy it when I get the opportunity to do it. Some uncut guys suggest it because they, like me, like the feeling of extra closeness of sharing an intimate part of themselves with someone else.
 
you learn something new every day...i wanna do that!
 
Had an uncut stud slip his ample foreskin over the head of my cock and jack is both off to completion. Beyond belief! Fullfilled a long time fantasy.
 
Done this with a few guys, cut and uncut. I found it easier to accomplish when soft. (Erect, my cock stands almost straight up...which could lead to some interesting docking gymnastics, I suppose.) It's very hot and intimate. If your partner's cut, it's like two cocks sharing a foreskin. The first cut guy I tried this with had a lot of precum, as do I. Indescribably delicious.
 
take a kiwi.
peel kiwi.
microwave kiwi until body temp.
re-shoot kiwi series.

close approximation?
maybe a hard boiled egg?