When I get hard, my foreskin cover the glans complete.
First I touch the skin softly and move it a little bit up and down... very slow and soft.
Then I move more up and down to see more of my purple head... after a few minutes I pulled the skin back and hold it back to touch and play with my big red glans. It's a very hard feeling for a boy with foreskin ;-)
Now the movement goes faster and faster and the foreskin goes up and down, harder down and softer up... and then... it comes...