In order for this to make sense, just pretend they were secretly going out during the movie. Or not pretend, because it probably happened anyways.
Erik smiled contentedly as Charles walked into the room, throwing his newspaper down on the coffee table before plopping himself down right on top of his lap and leaning back. Erik had been sullenly staring at the fire blazing in the dimly lit room, reminiscing on better times when Charles had decided to join him. Now, he couldn't remember why he had been so sad at all as he breathed in the soothing scent of his hair. He wrapped his arms around the other's waist and the telepath quickly placed his hands on top of his. From its spot on Erik's chest, Charles's head turned upward to smile at him lovingly. Erik smiled back, then brought his hand up to touch his face.
"You got…" he whispered, as he plucked at the other man's cheek, "and eyelash…"
Charles brows suddenly burrowed, and he brought his hand up to his face as well.
"Where?"
"I got it," Erik triumphed, as he held up his finger with the aforesaid object, right in front of Charles's eyes.
Charles stared at it confusedly for a while before Erik leaned down to whisper in his ear, "Make a wish."
Charles laughed, "My friend, I have not wished on eyelashes since I was just a boy! Do you still believe in these things?"
Erik nudged his nose into the crook under Charles's ear. "Of course I do. I believe in wishing on dandelions, stars, the time, and most definitely eyelashes."
"For a man who had to grow up pretty fast," Charles laughed. "That is pretty childish."
"Call it what you want," Erik teased. "But someday when your wishes don't come true you'll regret not trusting in the power of eyelashes."
"What wishes? All my wishes have come true," Charles wiggled his eyes cheesily and stretched his neck to land a quick kiss on the other's mouth.
"Oh, stop it. You know there's something that you want. Please just humor me and make a wish."
"Fine," Charles agreed and squeezed his eyes shut with a huge smile plastered on his face. After a few moments, he animatedly blew the eyelash off Erik's finger.
"There you go!" Erik cheered. "It blew away on the first try, that means it's coming true!"
"It better."
"What'd you wish for?" Erik asked.
Charles elbowed him lightly in the ribs. "I'm not telling you! Then it wouldn't come true!"
"Honestly, Charles? Do you really believe that?"
"Coming from the guy who believes in wishes upon inanimate objects in the first place? Your argument is invalid."
Erik shrugged.
"Well, I guess I'll find out sooner or later."
A few months later, as Charles sat in front of the very same fire, staring bleakly at its flames, rubbing at his now-useless legs, he felt tears prickle up in his eyes.
You lied, Erik. You lied. You said my wish would come true. I wished that we would be together forever. Where are you now?