A significant moment could be when Arjun gives Riya a special gift, like a piece of jewelry or a hand - written letter expressing his feelings. This shows his thoughtfulness towards her. Then, when they celebrate their first anniversary, reminiscing about all the good times they've had so far, it cements their relationship. Also, if there was a time when Riya was sick or in trouble and Arjun was there for her day and night, that would be a key moment in their love story.
One key moment could be their first date. They might have chosen a beautiful park, and as they walk hand in hand, they realize how much they enjoy each other's company. Another moment could be when Arjun defends Riya from some bullies or mean comments. It shows his protective side towards her. Also, when Riya cooks a special meal for Arjun for the first time, it deepens their bond as they share this intimate moment together.
Perhaps the moment when they first say 'I love you' is a crucial one. It's a big step in any love story. Also, if they have to face some kind of family opposition, the moment when they decide to stand together against all odds is key. And when they travel together for the first time, exploring new places and creating memories that are only theirs, that's also an important part of their love story.