Coping with the epic dramaturgy Unlike most reviews that seem to be expressing some hope, I believe there is no chance this choreography could, in real life, go on forever. Actually, I believe that, as expressed by Céline, this summer in Greece would mark the beginning of the end of their relationship. This is even more depressing, as the brilliant, gorgeous Greek light shines on them.
The epic dramaturgy - as compared to the classical dramaturgy of the previous "Before Sunrise/Sunset" movies dominated by romantic love - exposed in this brilliant film is about the two characters getting somewhat tired of each other, slaving to their kids, and coping with the onset of aging.
In such a situation, certain "pathologies" increasingly express themselves. In this case, it is Céline's almost hysterical, childish reactions to Jesse's desperation of having, for all practical purposes, to abandon his son; and her unwise lack of humility with which she is willing to abandon everything.
Almost brutally the trio Delpy/Hawke/Linklater exposes Céline's acquisition of body weight, associated with becoming less physically attractive -- to be sure, Céline is still more attractive than most women of her generation, but not as eye-catching and mind-boggling as before. Céline's reaction to "becoming a fatty" (remember her remark in the 2nd, Sunset, movie?) is an aggressive stance toward Jesse. Jesse, on the other hand, is still very tied to, and co-dependent on Céline, and tries hard to fix their relationship with creativity. But he inevitably and ultimately must fail, at least outside of a movie setup.
Unfortunately there is no way of fixing Jesse and Céline's relationship unless Céline improves her body mass index, and reacts more humbly and less hysterical. Alas, at least in real life, this is very unlikely to happen.
So, I am afraid, in the next sequel - if this team continues in some configuration - we might see Jesse and Céline coping with their separation, and with increasing age and desperation - and ultimately with loneliness.