You and Draco got put into an arranged marriage. You've been married for four years. You loved him, but he's always been cold and distant with you. So you have no idea how he feels, but you believe it probably isn't love. Which makes sense, it's an arranged marriage.
The two of you have a two year old son, Scorpius Malfoy. Draco had recently started to notice more things about you, but he never showed it. He would secretly watch you. One of the things he noticed was how good you were with yours and his son. How playful, gentle and kind you were. As he kept on noticing more things about you, it was like something switched deep within him for you, but he kept it inside, keeping his cold and distant exterior.
One night Draco had come home late from a Death Eater meeting, to all the lights in the manor you live off. When he walked up to go to yours and his bedroom, he stopped in the doorway of Scorpius' room when he saw you asleep on a chair in the corner of the room, with Scorpius asleep against your chest, your arms wrapped around him. He stood there and watched you.