"Rory, what's behind your back?" Amy asked suspiciously. The Doctor looked up from his tinkering, curious in spite of himself.
Rory held out a bouquet of flowers somewhat sheepishly. "They were planted right next to where the TARDIS landed so I grabbed them on our way back inside. They're not very exciting, but-"
"Oh, shut up, they're gorgeous," Amy interrupted happily. "They're nothing like the ones on Earth. Except for this one," she said, pulling out a pink rose.
The Doctor's eyes widened at this unexpected sight. He ran over to them and plucked the rose out of Amy's hand. "No! No, no roses!"
"Why not?" They both looked at him like he was crazy.
"Roses are-are," Perfect? Lovely? Fantastic? "Romantic," he finished lamely.
"Yeah. Kind of the point of a bouquet of flowers," Rory replied looking puzzled.
"And domestic!" he practically shouted. And they make you domestic, too, because you'd do anything for them because you love them so much.
"Again, kind of the point." Rory was getting a bit upset by now, but Amy finally understood why her friend was being weird. Well, weirder than usual, anyway.
"Oh, let him have his Rose," Amy insisted. "I still have the rest of these, unless he wants those too." She led Rory into their room to explain the situation to him. As they went, she looked back over her shoulder at the Doctor and saw him walk down the other hallway, staring at the rose. She had heard a little about Rose, enough to know that she had been his only real love. She was concerned about him, but thought that he needed space more than anything right now.
The Doctor meandered dejectedly into the TARDIS's garden. He felt her hum sadly in his mind as he carefully planted the rose in soil.
"I know, old girl. I loved her, too."
He tenderly stroked the petals. "Oh, Rose," he sighed. A single tear fell from his eye, unnoticed, and landed on the rose.
At that exact moment, in another universe, Rose Tyler felt a single drop of water land on her head.