There are many kinds of bonds that two beings can form.
Among humans, Vows and Oaths are taken, and the punishment for breaking them depends on the terms of the contract. Naturally, at the time of marriage, very few couples take such Oaths.
But things are very different for beasts—and even more so for dragons.
Dragons can form several types of bonds, and the strength of those bonds determines both the punishment for betrayal and the depth of their connection. The stronger the bond, the more it affects the two bound together—physically, emotionally, and even spiritually.
The weakest bond is the mating mark. When a dragon claims their partner during heat, they leave a mark that binds them as mates. Through this, they can share emotions, fleeting thoughts, and even feel each other's pain and relief to some extent.