CrackRabbit
Lifer
This is only relevant if you define a marriage to be just a contract.
The problem is that since you demand that the government recognize your contract it is not just a contract between 2 people.
As well as the fact that you probably have several contracts yourself with non-human entities.
How does allowing a man to marry his couch affect your marriage? Are you afraid that if we recognize object sexual marriages you will start feeling an overwhelming urge to co-populate with your toaster?
Hey just because you like to stick your wang in a toaster doesn't mean other people do.
Besides I have never seen a toaster be able to consent to anything.