Two year old randomly doesnt want to sleep in own room?

Our two year old has slept in his own room for almost a year now, we never had enough bedrooms for him before. He spent a week at grandma's and now is trying to pull what he gets away with there, here. The first two nights he went back into his normal routine of bed. Last night, he caught a late 5 minute cat nap and was too refreshed at his normal bedtime. We tried letting him scream it out. We tried sitting in there with him, but the end result was we had to lay with him til he fell asleep. Now tonight, he pulled the same tantrum at bedtime, and beings its now 2hrs past his bedtime, his dad is in there with him til he falls asleep again. How can we break him of needing someone in his bed again like two weeks ago? I don't want to revert back to a pacifier because he's on his 2nd month without one. But the past two nights is nothing but tears and screaming everytime we turn his lights out and try to leave. What do I do??