All the Ghosts of Christmas have a very good working relationship, but one must notice Present and Yet-To-Come seem to be especially close, with the latter coming to the former for catchphrase advice and finally breaking his haunt silence to chew out Clint for getting him to retire. Seems random.....until one remembers The Reveal Present is the original Scrooge. Given unlike Past ("I've been dead for 40 years") and Present ("I did research and then took over after the old guy retired") there is no indication Yet-To-Come is a Legacy Character, he must be the very original and so has been friends with Scrooge since the 1840s!
Given the fact that Present is Scrooge it makes sense why he wants to marry and have a family. In life, he never had one but he almost had as the novel reveals that he was once in a relationship with a woman called Belle. However, she ended their relationship for he was becoming more greedy. The final shadow of the past he is shown is Belle married to another man and with children. When Clint shows him the life he could have with Kimberly, he likely remembered the fact that he had missed his chance of a life with Belle.
When Present shows Clint the scene of a loving family on Christmas morning, how is Clint able to magically change the scene to show the family that Present wishes he could have? Simple. Clint is a master of taking charge of a situation and manipulating it to serve his interests. He's been analyzing and criticizing the ghosts' tactics all night and is constantly turning the tables on Present. This is just one more instance of using Present's own tactics better than him. And it also foreshadows Clint's eventual role as the new Present.
When Clint brings up the Christmas Carol story to Marley, Marley angrily comments on the amount of adaptations it received that "nobody asked for". It feels weird for a ghost to care so much about that, except that Marley is the original Jacob Marley, just like Present used to be Scrooge. He's not just annoyed at the adaptations existing, he's annoyed at how often his life and death is being used for entertainment.
