I'm not sure I get the Chianna/Jathy thing, that affair doesn't make a lot of sense and is more soapy than dramatically interesting.
I think it's because chiana and Dargo have different views what their relationship is and where it's going. Dargo wants a loving and committed relationship where they can settle down together and assumes that Chiana wants the same when in reality Chiana is wanting a more fun less serious type of relationship and is feeling trapped and tied down by Dargos level of commitment.
She is too immature and doesn't know how to handle the situation so instead of talking she just does something recklessly impulsive that will, in a sense, free her from the situation she's trapped in without any thought to consequences. Jothee also has Dargo projecting an idealised view of who he is and how their relationship will be onto him and doesn't know any of these people enough to care that much about consequences.
It is very soapy and melodramatic.