Hoshigari Omega wa Sora ni Naku

Ivan, an alpha wolf beastman living alone in the forest, is visited by Theo, an omega half-beastman. Ivan, not even knowing Theo's name, is captivated by his pheromones and spends the night with him, only to wake up to find Theo gone. Furious at being used and discarded, Ivan can't forget Theo and, driven by sheer determination, finds him. He then declares that he will become Theo's mate to take responsibility for their relationship. However, Theo dismisses Ivan's offer, claiming he only wanted a child...