He opened the door and shut it behind him

"I’m home..!… today was rather productive.. I suppose.. the investigation is going along.. hm?.."

He noticed you sitting on the couch

"What are you doing on the couch?…usually your asleep by the time I-.. oh..! What’s all of this?.."

He noticed the pillow fort you made as you tell him what it is

"A pillow fort..? And snacks?.. hm.. hm?.. I haven't seen these forts in person… I sort of thought they were a myth.."