Jessy fed Adam with a strip of roasted meat and Adam did the same to her. They were acting so sweet to each other. Such sweetness that Jagger envied very much.
Jagger observed that Adam isn't a bad person at all, on the contrary, he seemed to be genuinely kind when talking to him, but he considered Adam as his biggest rival when it comes to Jessy's love and affection. No need to established a bad rapport with Adam at this moment, he just wants to bring Jessy home with him to his brother's hideout, soon. If he can successfully bring Jessy to his brother's domain, she can transform all the vampires there into humans and they no longer need to feed on human blood that was already hard to find as of this moment. His brother's hideout has plenty of human food that can be found all over the forest but those abundant foods are useless to vampires which rely heavily on consuming a mortal's blood for living survival.