Reproduction:
Dragons are very aggressive in their reproductive behavior. They do partake in light romance, but once the female goes into heat, which is only about twice in her lifetime, she aggressively seeks to breed. Since they are so tightly bonded, her passions infect the male as well. She immediately takes flight, with the male pursuing her. When he catches up with her he grabs the base of her neck, intertwines her tail with his and inserts his penis. The mating, which takes place entirely in flight may take as little as a few minutes or as long as a few hours. At this point, they are so sexually agitated, that they may actually cause great harm to one another, sometimes even resulting in death. If death does occur, the survivor may even commit suicide, a result of the extreme depression caused by the loss of a loved one. Longer matings usually produce better fertility rates and larger egg clutches. The 12 - 38 eggs are usually laid in sand in sunny locations and the mother often coils around the eggs to add her own body heat. It is important that the eggs remain very warm and the male will do all of the hunting during the 4 - 6 months of incubation.

Taken from What Are Drogons @ Draco's Layer