Big difference!
Joyce was a married accountant with children when he entered politics.
His new relationship circumstances are more private ( now public) than political.
Shorten on the other hand 1st married an ex liberal politicans daughter.
Then had an affair with and married the daughter of the Australian Governor General.
With Shorten nothing escapes his political machinations - marriage, truth, loyalty, morality, etc
All are tools for Shorten to use to achieve his goals.