I have a 6 year old Cali Kingsnake almost 5 feet long. My corn snake is a little over a year old and about 3 feet long. Ive never held them at the same time as I was nervous about letting them meet becuase eventhough neither are aggressive at all kingsnakes pray on other snakes in the wild. Can they be held at the same time

Nope not unless you want to end up with one very full king snake and thats all. King snakes eat other snakes including corn snakes.

if you are watching them then yes because if anything happened you could stop it

Retrain them when they meet because the king snake will try to attack the cornsnake

i agree with jcbrock1
king snakes eat other snakes i work at a zoo and when we were breeding the king snakes the female ate the male snake .so if you are sick of having 2 snakes then yes but know this your corn snake might be to big for the king snake to eat and then you would have to cut the corn snake so that the king snake would live