He can't help but smile - she sounds so much like herself, and like the woman she's become. In the moment, it's not hard to see her affection for him, whatever form it might take right now; she'd loved him long before either of them ever broached the subject. Mulder feels it, and he's missed that feeling - but it's coming back like a knife between the ribs.

"I've slept," he tells her, even if some part of him already knows he's lost. "I'll be fine, Scully. Really."

He gives the couch a little test bounce, as if to say see? this'll be fine.