Rabbits and guinea pigs should not be kept together.
To begin with, rabbits have very powerful hind legs, and can severely hurt a guinea pig, even if they are simply playing. It does not have to be malicious.
In addition rabbits carry a variety of bacteria that can be harmful to guinea pigs, but often do not show signs in the rabbit.
Spay or neuter your bunny, and get him or her a bunny friend. Get your guinea pig a same sex guinea pig friend. Everybody will be much happier.
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