ok people, first things first, all of you Jack x Jane or Mary x Bert shippers who will get mad at this had better leave. Not everyone has to like the same ships, but don't try to force other people into liking canon ships.
Jack was dejectedly (a/n is that a word?) cleaning a lamp. Ever since Mary Poppins had left, he had been quite depressed. She was all he could think about. He remembered her coming to him before she left.
flashback
"Jack?" Jack turned to see Mary Poppins behind him. He noticed that she looked very sad, and there were tears starting to form in her eyes. "Is everything all right?" he asked her, putting his hand on her shoulder. She sighed. "I have to leave, and I just wanted to say goodbye." her voice cracked on the last word. "The truth is, I hate having to leave you, and i just wish i could stay." a single tear rolled down her cheek, and Jack wiped it away. "Its all right. You know I'll wait for you every time you go. I'll never stop waiting, even if it takes a hundred years." Mary Poppins looked at him. Jack pulled her into his arms. She rested her head on his chest, and he felt her relax in his embrace. They stayed like that for a long time. Finally, Mary Poppins pulled away. "I have to go." She whispered, before walking away.
Jack still remembered that moment, and thinking about it made him miss her even more. So when he heard someone behind him, he assumed he was imagining it. But when he turned around, it was sure enough Mary Poppins. For a moment he couldn't say anything, so he simply embraced her. Tears ran down both of their faces. "I'm so sorry i left." Mary Poppins whispered. "I'm here to stay. I swear I'll never have to leave you again." Jack just held her for a few, long minutes. After a while, he pulled back slightly, enough so that he could look her in the eye but could still keep his arms around her. "I never thought I'd see you again." he whispered, putting his hand on her cheek. She leaned into his touch. Jack leaned closer, so that their noses were almost touching. "But now you're right here." he whispered before capturing her lips with his own. It was everything he had always wanted. He could feel their hearts beating as one. When they finally pulled away, Mary Poppins smiled. "Thank you Jack. I love you." she said, resting her head on his shoulder. "I love you too, Mary Poppins." he said.