Alternate it repeatedly from one to the other

From Create Your Own Story

The syringe measured 5 liters and was more than half full, when Jenna felt another bout of vomit coming on. Luckily she got back to the bowl in time because that second lot was almost as much as the first.

You make sure not to lube the end of the syringe, so it makes a good seal on her asshole. Slowly but surely she takes the full mega-load into her anus. As you take it out, you wonder how much will squirt out with it, but Jenna does a great job puckering up her butthole tightly as you remove the syringe. Not one drop is lost.

Next she has a small tube shoved into her ass and the load is drained back out into the bowl. At the end she is squirting and straining so much the tube comes out and she prolapses a muffin sized ball of flesh. More squirts of semen follow but still not a trace of brown. This time though, as it is put back into the syringe, there is toto much to fit in! Jenna must not have vomited all of it after all, and the rmaining jizz actually passed through her with all of the convulsing and excitement.

Luckily a second syringe was prepared and soon you have 8 liters of sperm ready to inject.

To teach her a lesson for hiding all that semen for so long you consider injecting it all into her pee-hole.

Do you...