There are many words that can describe Jason and Medea.  One word is "infatuated."  Both are infatuated with one another and see in the other a reality that is tinged through the lens of infatuation.  Jason recognizes that Medea's help can prove to be invaluable and is infatuated with this possibility.  Medea is infatuated with Jason and covets him. Both of them are infatuated with the other.  The word "disrespectful" can be used to describe both of them.  Both Medea and Jason disrespect the natural order of things in order to accomplish their own personal goals.  Medea disrespects the natural order of respecting her father and her home in helping Jason, who in turn has no problem using Medea as a means to an end, something that becomes evident later on in their marriage.  Between both Medea and Jason, there is much in way of "selfishness."  Both of them do not focus on keeping an eye to the maintenance of the social order.  Rather, their beings are constructed as shallow exercises in which their own needs and desires are satiated.  It is for this reason that both of them experience fairly horrific endings as both of them are solely driven by their own condition of being in the world.  Interestingly enough, another term that can describe both Jason and Medea is "successful."  Both of them are successful in accomplishing their goals.  Jason retrieves the Golden Fleece.  Medea is successful in her attempts to help Jason and does, for a time, win him as her own.  Finally, I cannot help but feel that both of them end the narrative steeped in the "contingent."  There is little in both that is "built to last" for the future.  Both Jason and Medea have become so entranced by the present tense and that which is temporal that they become beings who are "contingent."  In this, both of them reflect the very challenge of what it is to be a mortal.