Disclaimer: I do not own the characters, plot, or anything else of the Game of Thrones/ASOIAF series.
This is an idea that has been floating around in my head for awhile, and I thought I would go ahead and try to bring it to life. If you don't like it, OK, if you do, awesome!
Cersei
"Push, your Grace, you must push!" exclaimed the Grand Maester, standing in front of the birthing bed, directing the actions of all of the midwives crowding around her. "Push, your Grace!" Who is the one here who has given birth here? You or me Pycelle!? Cersei though, She would have sent the feeble old man out of the room if she had not heard one of the midwives say "I can see it's wee head your Grace, only a little further!" With one last push, Cersei felt her child enter the world, and was surprised by how much this birth was far more easier than the only eleven moon old Joffrey.
Something was off though, she heard nothing, no screams of a newborn, no wailing that would seem to never end, only the midwife calling out to her; "A healthy, beautiful boy your grace." Cersei immediately cried out "Let me see my son!" The midwife passed over the small bundle, and there was her second son, her second little cub from her brother, Jaime. Only, her son did not open his eyes, he remained silent, her heart sank. She began to panic, she held the baby close, and began to plead with him; "Please little cub, open your eyes, show mama that you live."
As if to answer her begging, her son opened his eyes, except there were no Lannister emeralds looking into hers, but Baratheon sapphires. No! She screamed in her head. Let it not be! She carefully pushed back the blanket covering his head and upon his crown lay a small tuft of coal black hair. I was so careful! Despite the panicked expression on her face, the small infant broke into a smile and extend a small hand up to her. This small action washed away all hate and anger she had suddenly developed for this child, her child.
She felt a hand on her shoulder, and looking up, she locked eyes with her twin, and lover, Jaime, a extremely solemn expression on his face. "I was so careful!" she hissed under her breath, "How could this happen!?" "Well, it happened, and there is nothing we can do about it now, save for killing it." "No, I will not kill my child, son of an oaf he may be, he is my child!" "Very well, if you had rather live with a reminder of him being inside of you everyday of your life, so be it." With that, he stormed out of the birthing chamber.
Cersei had only a brief time to dote on her son all by herself before the door to the chamber slammed open. The Oaf. King Robert Baratheon barged into the room, a great pelt of a stag in his arms. Setting the pelt on the edge of the birthing bed, Robert edged to toward her, a look of curiosity on his face. He nodded towards the bundle in her arms, she looked down at her son, smiled, and said proudly; "You have a son your grace."
His bearded face broke into the biggest smile that she had ever seen on him; "May I hold him?" Cersei was surprised by the gentleness and care with which he handled the child. "Have you thought of a name for him?" he asked, still absorbed with the child. "I was thinking Tywin, for my father, or Steffon, for yours." He chuckled, and responded with "Steffon, a good Baratheon name for what will be a great Baratheon stag!" he laughed a booming laugh, and little Steffon gurgled happily.
Robert handed newly named Steffon back to her, and when she ran her finger along his nose, he gurgled again and grabbed her finger with one of his hands. She laughed merrily and smiled wider than she was already, noticing that Steffon's eyes had turned to look out of the open aired chamber to the ocean. "He'll be a sailor." she said "Like my father before him." Robert added. The royal family together gazed out of the room towards the black clouds forming on the horizon.
With the storm, came the fever, and it burned through little Steffon like a wildfire, his little wheezes echoing from where she held him. She would not let Robert take her away from him during what might have been Steffon's final hours. Robert sat in the corner, snoring loud enough to rival the thunder rolling over the city. Eventually she fell into sleep, still listening to his breathing slow down.
Cersei awoke late in the morning, the sun shining through onto her and Steffon. Steffon! She looked down upon the bundle in her arms and could not notice any movement. Panic set in, this time worse than after he had been born. She shook him, trying to repeat the process that she went through after his birth; "Wake up little cub, open your eyes again for mama."
Sure enough, the sapphires shined up at her and the smile broke onto his face again. "Robert!" she called "Robert, wake up!" he stirred, yawned, and stood up. "Steffon beat it, he beat the fever!" He rushed over, peering down into their sons face, causing them both to smile even wider. A knock rang on the door, "Come in!" called Robert. The door opened, and there stood his brother, Stannis, with the young Renly peering from behind his legs, and Jaime looking over his shoulder. Stannis edged forward, stoney faced, but with his eyebrows raised, clearly asking the question; Well?
Cersei smiled at him, one of the only times she ever would, "Come forward, meet your nephew." Stannis walked forward, a hand on Renly's shoulder. "This is Steffon" Robert stated, pride clear in his voice. Cersei shifted her son so that the very curious Renly could see him. "Just like father!" Renly exclaimed. "Yes, just like father" replied Stannis, enamoured with the newest addition to his House.
The Baratheons, along with the Lannister in the white armor, came together in a brief moment of love and unity, one that would never be seen again between the five adults.