What If Robert and Cersei Had A Son? (Game Of Thrones)

One of the biggest issues in Game Of Thrones and probably the most important one that caused a lot of death and conflict was Robert lack of a true heir to the iron throne. But what if inatead of brothers, and bastards Robert Baratheon had a trueborn heir with his wife Cersei Lannister? #asoiaf #whatif #gameofthrones