First off, this takes place in an alternate universe where Harry broke up with Ginny ( had no children ) with Hermione doing the same.
It was a cold winter day. Harry Potter was devastated about his recent fight with Ginevra - a sad memory that will forever haunt him. Christmas was lean and lousy and being in a fight definitely did not dispel any of the hard feelings. Harry decided to relieve stress by taking a walk in the bustling city of New York. As he walked down the sidewalk, all he could process was a faint blur of light. It was a moment of bliss for him seeing happy children and couples happily walking with gifts and cups of hot chocolate. Inside, he knew he wanted the same - he cannot forgive himself for getting into that fight, possibly dispeling a happy potential future where his children could have grown up to follow his steps.
As he was starting to gain focus, the city was filled with familiar faces and old friends. One of them stood out from the crowd, and that was a miserable Hermione Granger that clearly had a no better time than Harry. He wanted to go up, yet he was filled with hesitation. He eventually walked up to her, for comfort.
"What's wrong?", asked Harry gently.
Hermione took a pause. Her memories were flashing before her eyes; getting distracted. She could not help but try focus on the happy memories, the endless days at Hogwart's where they would rebel against the teachers and confront Voldemort - the memory that stood out the most. Hermione could faintly remember the rush of hope that she felt when Harry was so close to defeating Voldemort, though, it was all over now. She could not let anything out, she was just too depressed.
Finally, she decided to let out a word.
"I... had a problem with Ron.", slowly and sloppily answered Hermione.
Harry proceeded to hug her, and Hermione started dropping tears - firstly showing no interest, but then she proceeded to hug Harry back, feeling the warmth of Harry. They were practically glued together now - both of them were comforted by eachother and they were glad they met.
Hermione slowly raised her head up to Harry, softly kissing him on the lips, which were soft, pleasant and warm. They continued for a good 3 minutes, though, from their perspectives, it felt like a lifetime of sudden bliss.
"Would you like to get a cup of coffee?", offered Harry.
Hermione giggled, and accepted. On their way to the coffee house, they held their hands together and felt like a couple.
Afterwards, they both went home to sleep. They were both enlightened.