Snip the boys

if you both really don't want kids, then snip away

and i've had a colonoscopy. the prep is a pain in the ass (literally), but it's so worth it. especially if you've had GI issues or have family history. colon cancer sucks.
 
Do they still use cameras like this for it?

2323693468_f65107670a.jpg
 
Or.. you could ask her to give you a BJ, and then say something like, "You're brother uses more tongue and cups the balls"

VIOLA, no more kids.
 
Yes on both counts. Colonoscopies are mandatory when you're as old as you.

Vasectomies don't affect sex or libido, only the presence of tadpoles in your juice.