Big Boy bed drama

We bought a big boy bed for Pepe almost one year ago. His room is pretty big and it easily accommodates the crib and big boy bed. We have been talking about switching Pepe to the big boy bed for a while now, but since t here is no pressure -he does not insist or especially like the big boy bed, and he does not get out of his crib - we procrastinated. Until New Years Eve. I was at the neighbours' house and Chris, in charge of bedtime, decides to have Pepe sleep in the big boy bed. It worked beautifully! He slept through the night, and in the morning, the biggest presents ever, he went downstairs and we found him there when we woke up. However, it was a downward spiral after that. Every single night Pepe would get our of the big boy bed, start playing, come downstairs. We'd put him back in the bed, tell him that if he gets our he'll go into the crib, out him in the crib bc he did get out of the bed, listed to him screaming, trying to sleep on the floor in his room to help him fall asleep, listening to more screaming, and then giving in and bringing him in our room, "sleeping" worried that we might hurt him or that he would wake up, which he did, at ungodly hours like 5:00am or 4:45 am. Last night Chris was out and I had a crazy day interviewing 8 psych fellows in the am, dealing with 80 emails acquired between 9am and 3pm, and I did not even go through the entire process, just brought Pepe into the bed with me at 9pm and we both slept until the morning, sans Chris, who supposedly tried to get into the bed with us when he got home but there was no room. So now Pepe is talking about sleeping with mommy and daddy every night. We are biting the bullet tonight - took all the toys out of hims room and we are going to stay strong and not take him into our bed. We'll see. I am not convinced I am going to be able to do it.