I posted the below on another forum in response to someone saying that Jac had no right to be upset or expect consideration from Joseph as she'd dumped him for her job. I thought I'd share here too.
Jac and Joseph's break up really wasn't as simple as one dumping the other because they were selfish. They both had different aspects of their lives that had to take priority and they couldn't see a way through it. They almost broke up because they loved each other so much rather than not loving each other enough - the was too high a chance they'd both have to give up too much to please the other and they'd end up resenting or hating each other - back to the mess they'd been in for most of the previous 3 years.
Jac is surprisingly self aware, she probably knew (or was scared) that she would end up mucking up and hurting Joseph or even worse Harry. Unfortunately, due to her background, I think she does need to feel that she comes first as she never has had that - most people do with their parents, at least when they are young but as she has never had that reassurance or stability she craves it now and Joseph was always (rightly) going to put Harry before her. Then, as Mark says having to jump every time Faye calls as he is scared she'll take Harry and finally his job. Jac would have been way down that list and what would she have? No high flying surgical job just a GPs position talking to patients constantly rather than actively fixing them (her idea of professional hell I imagine) and inlaws that hate her. It might have worked if Harry was her child as well, they both loved him more than each other, but whilst I know step families can work well, I think Jac might have struggled. Especially if she was kept at arms length as Joseph promised Faye he wouldn't let Harry forget her and no-one would replace her as his mother and also, that they'd be waiting for her to return.
Finally there was the incredibly high handed way he did it. He had obviously been talking to Elliot, the GP surgery in Penrith,, he’d even sent a strongly worded resignation to Hansenn without even discussing the possibility with his grilfrend? Yes he asked her to come with him but it was very much, I’ve rearranged your life, like it or lump it. If that was an indication of how the decision making process would work in the marriage, I don’t blame her for being apprehensive! I do think that they belong together and could have made it work but not with one person (in this case Jac) making all the sacrifices. No relationship can work long term on those terms in my opinion.