Guinea pigs are not the same as rabbits and they don't have to be neutered to live together. However, they do need a lot more space than most people realize. A pair of young males needs at least 10 square feet between them and more is better! The average "pet store" cage is between 5-6 square feet. Much too small!
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry