Fall
It was his favorite season and they were together. It was like the turning leaves themselves were whispering their blessing: Go ahead, Mulder. We're falling and you should, too.
He didn't want to frighten her with the intensity of his emotion (it had only been a few weeks, after all), but with her burnt orange leaf hair and clear blue sky eyes and pale, wispy cloud complexion, how could she not be his favorite, too?
And it hadn't really been just a few weeks, had it? Scully had planted the seeds of love, planted herself in his heart years ago with her smart mouth and her smart mind.
Walking with her now, hand in hand, her eyes sparkling, he realizes that those seeds have grown and it is high time to harvest their yield and share the bounty with her.
When the tether of their arms prevents her from moving forward, she turns to see him stopped beneath a tree with yellow-orange leaves and staring at the pavement.
"Mulder, what's wrong?" she asks, stepping close to him, concern marring her lovely features.
An impish leaf thinks he's thought about it long enough and uses his forehead as a springboard before drifting lazily to his feet, ending his musings. Meeting her eyes, taking in her troubled expression, he takes his chance. "Nothing," he says, but her brow only furrows more deeply in disbelief. He can't help the uptick of the corner of his mouth as he finally says, "I love you."
He watches her change like the leaves around them: her forehead smoothes, her cheeks flush, and her mouth curls into a shy smile. She bends quickly to pluck his leaf friend from his shoe, then presents it to him like a flower.
"I love you, too," she says as he takes the leaf from her. Maybe he'll frame it.
Draping his arm around her shoulders and drawing her close to place a kiss on her crown, they get back to their stroll, heading in the direction of his apartment.
This is definitely his favorite season.