Perhaps he needs more exercise in the evening?
Well......Kacee used to be up and down from her bed onto the big bed quite a bit. Now, she just does it once in awhile and I think eventually she'll stay on the big bed all night. She pretty much does now. Besides, if she gets cold, she'll come snuggle up to me.
Muffin never, ever got off the bed in her life! They can be sooooooooo different from one another.