At first, their relationship might be a bit tentative. Harry would be surprised to see Remus near his relatives' place. But as they start talking, Harry would feel a sense of connection. Remus could offer some words of comfort and understanding about Harry's difficult situation with the Dursleys.
As time goes on, Remus could become a sort of mentor to Harry. He could teach Harry more about the wizarding world that the Dursleys have tried to keep from him. Their relationship would grow stronger as Remus shares his experiences and knowledge. For example, he could tell Harry about the different magical creatures he has encountered, which would fascinate Harry. And Harry would start to trust Remus more and more, seeing him as a reliable figure in his life.
Remus might interact with the Dursleys in a very calm and collected manner. He would probably be polite, despite their rudeness.
One possible scenario could be that Remus has come to check on Harry secretly. Maybe he wants to make sure Harry is okay and see if he needs any help with his magic studies in secret, away from the Dursleys' watchful and often unkind eyes.
At first, it might be a bit awkward. Teddy has only heard stories about Remus, and Remus is seeing this young man who is his son in a way he never expected. But as they start to talk, they would find common ground in their love for magic and their experiences at Hogwarts.
Their relationship could start off with Charlie being a bit of a mentor to Harry. Charlie has a lot of knowledge about the magical world outside of Hogwarts, especially when it comes to magical creatures. Harry, being curious, would be eager to learn from him.
Their relationship might start off rocky. Minqto could be wary of Fem Harry due to her being different from what he's used to. But as time passes, he sees her determination and courage, and starts to respect her. This respect could then turn into a friendship.
One possibility is that Remus meets the Dursleys when he is on some sort of mission related to Harry. He could be there to assess the safety of Harry's living situation. He might find the Dursleys' treatment of Harry unacceptable and try to subtly change things. He could offer to help around the house in a very civilized way, making the Dursleys a bit confused as they are not used to such kindness from the wizarding world. This could lead to a series of events where the Dursleys start to question their own views about wizards and witches.
At first, Harry would probably be extremely confused and distrustful. He's been told all his life that Voldemort is the bad guy. But as Voldemort continues to protect him from the Dursleys, Harry might start to question what he knows. He could gradually become more open to listening to Voldemort's side of the story.
Well, Daphne in the 'Daphne meets the Dursleys fanfiction' would probably interact with the Dursleys in a very cautious way at the start. She would be observing their behavior towards Harry closely. Once she realizes the extent of their nastiness, she could try different approaches. She might try to reason with them, explaining how wrong it is to treat a child like that. When that doesn't work, she could use her magical abilities to disrupt their daily routine in a harmless but annoying way, like making the TV constantly change channels or the kettle never boil. This would be her way of getting back at them for their treatment of Harry and also a way to show them that there are forces they don't understand.
He might be very angry with them at first for how they've treated Harry.
Their relationship could become even stronger. After surviving the war together, they would have a deeper understanding and appreciation for each other. They might become more affectionate and open with each other, having seen the worst and still being there for one another.