to rejaculate is to use a syringe to put an already ejaculated load down one's penis and then sniff enough pepper(or whatever makes you sneeze) to induce a sneeze that contractsyour body enough to shoot the old load out with the vigor of a new one
I knew it was going to be a special evening when your mom came in with a syringe and a pepper shaker looked me in the eyes and said "I want you to rejaculate onto my face"