The Hydra's Breath: A Tale of the Viper Clan

Twins Pallas and Ixchel Viper are the children of Tlaloc and Velia and like their parents have rather grand ideas about love. For both of them, the idea of love at first sight isn't a lie and they believe love will see them through any situation, even if its a potentially dangerous one.
Pallas is a vampire rugby star and has fallen in love with the daughter of his coach, Myrtille. Unlike him, Myrtille is not interested in fantasy, romance or anything that distracts her from the difficult task of getting through another day. Pallas though is besotted and with it, oblivious to just how immature he appears to her.

Ixchel meanwhile is in love with a young Cursed figure within the main Viper Clan household... Garrett Hildebrandt. This poor figure is half-vampire and cursed by a demon, but Count Thibaut has found a remarkable use for his power and a way to 'manage' this curse. Ixchel and Garrett do love each other, but its clear there is concern in the family, especially given that Garrett's use is in one of Thibaut's unpleasant plans.
When Ixchel ignores the encouragement to forget about him, she'll use her close relationship with her brother to urge him to find the truth and what she can do to help. But all sorts of danger may lie ahead, especially if Pallas allows himself to be controlled by his elder twin.

This story has a steady and then fast pace, a lot takes place and it does include references to werewolves being used in fighting situations, potential assault, ableism and violence. It also contains mature romantic scenes.