The saddest moment in Jude the Obscure?

Perhaps the saddest moment in Jude the Obscure occurs when at last he has fulfilled his dream and moved to the university town of Christminster and finally takes the initiative to find his childhood teacher who had left for Christminster and provided Jude with the inspiration that has guided and directed his life. He comes to the door of his former teacher, who clearly has not attained the hope and promise of his life, which was to rise to prominence in the Anglican church, and Jude introduces himself and the teacher says: I don't remember you at all. What a line! - and it makes us think of the great title of this novel, and how in a way each of us is "obscure" - there are people we know and remember who do not know or remember us, to whom we mean nothing - and this must often be the case with teachers - who play such a huge, formative role in the lives of children - I think every one of us can recall the names of our grammar-school teachers - but who teach thousands of children over the years and can recall only the exceptional (for good or ill). Jude, as is his wont, recovers from this shock and re-builds a relationship with his teacher, and in fact encourages his cousin, Sue Bridehead (?) to give up her plan to leave Christminster and to take a job as the teacher's assistant. Jude's relationship to Sue will be dominant throughout the novel it seems - though they are cousins they have never met till they come across one another in Christchurch, and their families have feuded over a bitter divorce - but they agree to put that aside, and, from Jude's POV, he falls in love w/ his cousin (even before they met - based on a photograph - and he kind of stalks her for weeks in Christchurch before she actually looks him up) - but we can see the moral, ethical, and practical problems that lie ahead, most notably Jude's disastrous and hasty marriage to Arabella, who supposedly has disembarked for Australia - and they never took steps to dissolve the union. Jude is an intensely moral guy and he is already fretting about the problems that would follow if he were to start a relationship w/ Sue - so does he proceed w/out telling her about the marriage? Or does he tell her, and accept the consequences or outcome? He was tricked into marriage by Arabella, and it seems unlikely that he would be deceptive or furtive.