Jack is seeing Jessica through the lens of his suffering. Jessica is no more a monster than he is self. Jessica is the catalyst and bearer of her own karma, as is Jack. Jack's experience of this pain with Jessica is because of his own clouding over his lens of perception. Jessica probably feels like a young broken-hearted girl just looking for love, but Jack doesn't see Jessica the way Jessica sees Jessica. Jessica doesn't go to sleep thinking she is a monster, even if she were, her nature is to be and therefore to suffer, just like Jack.
Jack needs to take a chill pill, and either make love or get to a monastery and practice celibacy so that he does the least harm to the Jessicas of the world who are just girls whose hearts were broken by boys who thought the space of an embrace is a place of mental hell.
The pain of relationship is the pain of parting with the folds of 'self'... Jack is simply growing. And yes it hurts. But the pain is there regardless, how you choose to perceive it is where your practice is your work. What are Jack's knots, mental and karmic? What are the colors of his fear? And how does Jack conquer this demon he sees? It drains him after all, it is only him who can free himself from being put in a spell... but he must renounce what seems for what is, and that... is where the demons become as intense as your practice, but hey you know... small doubt, small realization, big doubt, big realization.
Om lalala, mmm-hey! (as my toddler says trying to mantra like mommy)
Om Ah Hum, Om Mani Padme Hum