This is kind-of based off of the x-men movies for Haru 93's mutant pairing contest....

Staring out the window as the sun set, Rogue twidled with the old, battered dog-tags that had hung around her neck for what seemed like an eternity, listening for a sound that she feared would never come just as she had everyday for the long years he had been away. "Looking for him again Rogue?" Kitty aproached the lone figure silently.
Jumping from her seat like she had sat on a pin, Rogue blushed at being caught, even by one of her oldest friends before sighing, "Yeah, but I'm starting to think that old Cyclops is right, he's never coming back."
"Who's never coming back?" A deep voice startled both of them as they turned to look at the tall, dark figure hiding behind the smoke of a glowing cigar.
"Wolverine! You're back!" Calmly, she walked toward him and gave him a hug.
"Miss me much?" He asked, a brow raised. Wow, she has really grown. He thought to himself as he looked down upon a young woman instead of the young girl he had saved what hadn't seemed so long ago, his face a perfect mask.
"Nah, I hardly noticed you were gone." She replied back, trying to fight the urge to jump into his arms and tell him how much she missed him while he was gone.
"Hm." He turned his back on her and simply strode away.
"Welcome home." He heard her say quietly and raised his hand to show he had heard her as he went to go see how the other x-men had faired in his absense, trying to get the picture of her with some guy's dog-tags around her neck out of his head and the feeling that he almost called jelousy but instead called fatherly.

2 weeks later

It was nearly midnight, but she couldn't sleep and sliped out of her bed and down the long maze of hallways to where the kitchen was, and there she had to catch her breath.
"What are you still doing up so late?" Wolverine looked up, an annoyed look on his face, "And what are you wearing? Shouldn't you have a turtleneck and pants on at this time fo year?" It was in the middle of december for goodness' sake and she was in a lacy nightgown that reached mid-calf.
"I'm eighteen, I can wear whatever I want thank-you very much." She spat back at him equally annoyed, turtleneck indeed, before sliding into the empty chair across from him.
After a few minutes of silence, he aske dthe question that had been bugging him ever since he came back to Xavier's school, "Who's dog-tags are those? Your boyfriend's?"
"No, they're yours." To prove her point, she undid the clasp around her neck before slipping the tags into his hand, still warm from her skin.
"Oh." He said, trying to sort out his feelings. Relief? Definately, he was glad she didn't have a boyfriend... but then he really shouldn't be feeling relief, she should get someone to take care of her. You can take care of her. A small voice wispered in the back of his mind, he forcefully shoved it away, he was practically a father -or heaven forbid a grandfather- to the girl since he was old enough to be one to her.
While he struggled to figure out his emotions, and fight back some very unwelcomed thoughts, he never noticed when she put her bare hand on his. So occupied in his thoughts, he never realized she was getting closer and closer to his face until he smelled her, and by then it was too late.
Since he was startled by the fact that she was kissing him, he didn't put up any guards. It was only natural, he told himself, that he would lose himself in the kiss since she caught him offguard and it was only natural that he kissed her back... This had nothing to do with the relief he had that she was single... Or did it?
When she finally withdrew her lips from his, he was still caught up in the onslaught of confusing emotions. "Rogue," He startled, but she held a finger to his lips.
"Shh." She wispered before kissing him again.
"Rogue, we can't." He finally gathered his thoughts, "I'm old enough to be your grandfather or worse."
"It doesn't matter." She told him softly, but feircely.
"And then there's the fact I almsot killed you." He tried.
"And I can't kill you, don't you think that's more important?"
"A- what?" He paused and realized it was true, he was the perfect match for her... But he would never admit it. He turned and walked out the door.
"Where are you going?" She asked, panick slipping into her voice.
"Leaving." He said gruffly. Trying not to let any emotion slip into his voice, the first time he left her at the school was hard, but this was pure torture.
"You'll be back won't you?"
In response he dropped his dog-tags on the floor, an unspoken promise passed between them.

He would come back as long as she had something to remember him by.