A lot of fans, myself included, believe that Jon Snow and Daenerys Targaryen will marry at some point in the series. Now that Jon Snow is the King in the North and Daenerys is about to conquer the southern kingdoms, a political marriage between them would unite the northern and southern kingdoms under a single banner. Hopefully, by then Jon Snow will discover his identity as Daenerys’s nephew and their House will be whole again. However, even though their marriage would unite the Seven Kingdoms there will be one serious long term problem.
This problem comes in the form of Daenerys’s fertility. In Season 1, the blood magic that lobotomized her husband and killed her unborn son also rendered her sterile. As a result, Jon Snow and Daenerys would not be able to continue the Targaryen bloodline the traditional way. Without an heir to succeed them, House Targaryen will be extinct and the Seven Kingdoms will be plunged into another civil war for dominance. After witnessing the horrors of the War of the Five Kings, it would be something Jon and Daenerys would want to avoid at all costs. The solution to their problem is a complex issue because Jon Snow will have to cheat on Daenerys to save both House Targaryen and the Seven Kingdoms in general. The reason for this is because while Daenerys cannot produce children, Jon can.
In order for House Targaryen to survive beyond Jon Snow and Daenerys, Jon will have to produce bastard children and use his and Daenerys’s authority as the king and queen of the Iron Throne to legitimize them the minute they are born. They would have to be careful and discreet with this because the last time House Targaryen legitimized their bastards resulted in the rise of House Blackfyre and a blood feud that lasted five generations. Also, producing bastard children is considered a social disgrace so Jon and Daenerys will have to find a way to make it look like it is Daenerys who gave birth to the children in order to avoid the same social stigma that persecuted Jaime and Cersei Lannister. Just as Eddard Stark sacrificed his honor to protect Jon, Jon will have to sacrifice his honor to secure the future of the Seven Kingdoms. Jon would do this with some reluctance because of his own upbringing as a bastard. Unless Daenerys finds a way to fix her fertility problem, this will be the only way House Targaryen will survive since she and Jon are all that’s left. If it comes to this, I hope Jon and Daenerys will raise the children with a healthy balance between Stark honor and Targaryen ruthlessness.
What is intriguing about the idea of Jon Snow and Daenerys marrying is that even though they are both Targaryens, their personalities are fundamentally different yet similar at the same time. While Daenerys can be ruthless and hot-headed, Jon Snow is cool and level-headed. At the same time, both of them have moral compasses, a sense of honor, and are compassionate towards unfortunate people. They really are like fire and ice, which is all the more fitting for them to be together. Also, if my predictions are right, then their future relationship is going to be complex beyond words. The reason for this is because they would marry out of necessity to unite the Seven Kingdoms and Jon would have his affairs out of necessity as well. As for the rest of their relationship, only time will tell.