When two men preform docking and while docked, they both reach an orgasm at the same time inside the foreskin. Creating a bubble of cum and making the uncircumcised penis ballon up.
Lapp and Joey where docking last night and I heard that they created a docking bubble while still docked together. I guess his foreskin bubbled up while still attached to his circumcised cock
When two men are unable to perform the act of docking due to both men having "the chop", a docking sleeve is used. This "sleeve" somewhat resembles a chinese finger-trap.
David and Richard both had the chop, so they bought themselves a docking sleeve, and docked the night away.