Finn and Rachel were so in love before Finn cheated on her.
About 2 weeks after their breakup, Finn was still trying to win Rachel back but none of it was working. He tried about everything, he stuffed love letters into her locker, sent her flowers, sang to her in glee club, he even interrupted her science class with the glee guys and sang Maroon 5's song "She Will Be Loved". Finally, he had enough.
After glee club, Finn went up to Rachel and kissed her right on the spot. Surprisingly, she didn't pull away. Once they pulled away Finn looked at Rachel and said "Rachel I love you so much! I'm so sorry about what I did, she doesn't mean anything to me, and please Rachel come back to me". When he looked down he saw that she was crying and then she told him that she loved him too. Then he smiled his adorable half-smile.
Later that night went to Breadsticks for dinner and they talked about why he cheated on her and they promised to each other that they would never hurt one another ever again. After that their relationship was back to normal. Rachel would laugh at Finn's dorkiness, Finn would watch Funny Girl with Rachel at least once a week, and most importantly they were in love again.