Just a random thought I had.
He knew he was connected to Voldemort somehow. He felt it, it was a deep connection. Meanwhile Voldemort also felt this connection, he felt drawn to Harry, all these years. The two would have episodes where they could even see into each other's minds. Harry couldn't help but dream of Voldemort. He would toss and turn until he woke in a sweat.
The two faced off in battle numerous times. Wand to wand combat, until one was temporarily defeated. The more they fought, the more it became apparent. That this feeling, this connection they believed to be hatred, was in fact love.
Eventually the two made it official and then even had a child together. Harry held baby Harrymort in his arms as Voldemort leaned over and smiled.
"Oh Harry, he has your eyes." He whispered gently.
""Oh Voldy, he has your nose." They smiled at each other and shared a passionate kiss.
"Ahhhhhhhhhhhhhhhh!" Waking up with a scream, "I have got to stop drinking pumpkin juice before bed." Said Hermione.