The Magic Three

Harry loved Ginny. But there was little passion. He loved her almost platonically, softly, sweetly, like fantasies of playing house.
Ginny fucked Malfoy out of spite. Malfoy was the person she thought would annoy Harry the most. She never expected it to be that good.
Harry had come to hex Malfoy for stealing his girl. They yelled, threw a few punches, then Harry pushed Malfoy against the wall and snogged him.
Three tries, three revelations. It took a while to calibrate, but three turned out to be the lucky charm.
Potter goes Poly, wrote the Prophet. The trio just laughed.