My 30 yr.old husband likes to act like a child? Is this normal?

He puts on this facade 90% of the time. For example, he'll coo at stuffed animals, and flap his "wings" (arms) when he's happy....likes to cuddle and be tucked into bed, or when I pet his hair. He likes to be reured and will talk like a kid too (with intentional slurs : "Oh noes, I gobbled my din-din (dinner)"). What's strange is he is a medical doctor for the air force. Is the stress of real life making him into a baby when he comes home to escape the death at work?