Scary Bunk Beds

So, we find Parker and Jack a bunk bed. We buy Jack all new bedding for his "Big Boy" bed. Jesse comes home and puts the beds together, and Jack and Parker are SOOOO excited. Everything was fine, until we go to put them to bed last night. Jack has this weird look on his face, when Jesse tells him he is sleeping in the new bed. He starts screaming! Not a normal scream. But, the kind that a wild rabid animal makes! Jesse gets him up, and lets him pee. Jack runs into his old room, and starts trying to climb up into his crib! Jesse goes to grab him, and he is hanging on to the crib screaming, NO!! He finally lets go, after Jesse pries his hands free. He continues to scream like a wild animal for about 30 mins! I guess he gave in, maybe to Parker singing Thomas to him, but he feel asleep!