Crib Refusal

Junior has been 2 years old for the less than a week and has decided that he is done sleeping in his crib.  He has never tried to climb out (that I am aware of) or anything.  The other night he just basically started screaming and was having nothing to do with going to sleep in there.  Dan finally went up and he said he wanted to sleep in the bunk bed that is in his room.  Dan laid down with him for about 20 minutes and then let him sleep there.  I was freaking out pretty much since there was nothing to keep him later from falling out of the bed.  Dan went up an hour later and moved him into his crib.  At midnight he woke up screaming mad.  I don't know what woke him up, but he was not going back in the crib.  I put him in his bed and he went right back to sleep and an hour later I went back up and moved him back into his crib because I still figured he would fall out of bed or get up and wander around the house or fall down the stairs.  An hour later he was back up again yelling.  I stuck him back in his bed and back to sleep he went and I let him sleep there until he woke up at 5:30am and started calling for. I was exhausted after that and didn't sleep much.  I'm pretty sure that I was listening to the monitor the entire night waiting to hear anything. The next day after work I ran into Target and bought a bed rail because I figured he was probably done with the crib now after we let him sleep in the bed last night.  I am now back on night / bed time duty for both kiddos.  I had a few talks and explaining with Junior about how he has to stay in his bed and cannot get out unless he calls for me and if he decides to get out then he goes back into the crib.  I then put a gate at the top of the stairs again in case he does decide to get up and try to wander around the house.  He did pretty well on night two.  We read a book in bed, talked some more about the rules of sleeping in the big boy bed and only once had to put him in his crib to show that I meant what I had said.  After 30 minutes and a little rocking and going in his room one time because he was calling for me he slept through the entire night in the bed.  He did wake up at 5:30am again, but I rocked him and told him he had to go back to sleep and he did until Dan went and got him up.  Amazing.  I really wasn't ready for this step yet and thought we had another 6 months with the crib.  This is all happening during the week so the true test will be this weekend when we attempt to get him to take a nap in there.  Wish us luck - the trials of parenting!