Last night's episode of Game of Thrones, "Mockingbird," saw several of the interpersonal relationships that have been building over the entirety of season four finally come to fruition in one way or another. In a new "Inside the Episode" video released by HBO, showrunners David Benioff and D.B. Weiss go into the inner workings of those relationships. Daenerys Targaryen and Daario Naharis finally pulled the trigger on their relationship, which has been full of sexual tensions from day one. "In season one, Dany's sexuality was central to her transformation from, basically, a piece of property to a full-fledged human being," says Weiss. "Dany's not really cut out to be a virgin queen, and Daario is a bad boy who seems like a good idea to her at this moment." In a surprising turn, Oberyn Martell offered to serve as Tyrion's champion in the trial-by-combat against the Mountain. "Oberyn owes Tyrion a great deal," explains Weiss. "Oberyn came to King's Landing to seek justice against those who had wronged him and, by demanding a trial by combat, Tyrion has given Oberyn a perfect opportunity to achieve what Oberyn set out to achieve, which is taking one of the big names off of his list of people who need killing." The climax of the episode came when Lysa Arryn witnessed a kiss between her new husband, Petyr Baelish, and her niece, Sansa Stark. In her rage, Lysa reveals that, even though her screen time has been limited, she has been integral to the plot of Game of Thrones from the beginning. "Something that becomes clear in the fifth episode, that's reiterated here in this much more emotionally volatile scene, is that Lysa and Littlefinger are actually the people who set this entire story in motion," says Weiss. "They've, arguably, had more influence on the events in this world than any other two people in the story." Game of Thrones airs Sundays at 9 PM ET on HBO.