Razaiel - Corn snakes are known to be cannibalistic. I don't care how long they have lived together, something could set one off one day and you could end up with one eating the other.
As 'cute' as they look curled up together, I promise you they are not bonded to each other, or care at all about the other one. Snakes are not social and have no use for affection or bonding of any kind.
If one corn snake gets sick, they both get sick. That means double the vet bills.. it's all around no good. Snakes living together are stressed.
Do them a favor and seprarate them.