Who knows why any of these characters feel the way they do. Jealousy? Larkin's influence on the charlataine over the years has faded considerably. He has tried to make it look like that was his own choice, but it's not that easy to forget how much he has invested (time as well as money) in the LaLa project, that has more or less become unusable for his part of the family. They can't freely spend time there anymore without being sucked into the amoral shenanigans of Stephanie Jarvis and her LapSquirrel, who have put the eyes of the world on his holiday home, scrutinizing every single move he makes, bagged or not bagged.
That makes perfect sense. Larkin was the knight in shining armor who took out a mortgage to help Fanny get the farmhouse, helped in the initial renovation, and gave money to Fanny personally ( he had just purchased a car for her a couple of years ago) and helped pay a lot of the overhead. I am sure after Daddy died, the pressure on him to help Fanny and maintain the dump increased significantly.
Fanny probably continued to love bomb him and play the little orphan who needed to be rescued. But suddenly, she comes into crazy amounts of YouTube and Patreon funding, and he was probably tossed aside as he was not needed financially, etc. Fanny begins to place her garish decorating plans into place at the Shittoo without consulting him and has steamrolled Larkin into making lots of decisions that devalue the place or cannot be maintained in the future or didn’t bother to consult him at all.
Then he has to watch videos with 25 year old boy band reject Snorts going freely into his family’s cottage and walking around like he was that Marquis. Punchable faced Snorts has crawled all over the Shittoo and knows everything about everything. He is super nosy. If just watching Snorts in 30 minute videos pisses us all off, being around him for hours or days would be intolerable.
I would imagine that the fight at Christmas was about concubine Snorts acting like he owns the place and being bossy and entitled, and Larkin was fed up with him and feeling like he was being excluded from using the property that he had to pay for with a mortgage and has been a financial and mental albatross for the past 15 years, especially dealing with constant “emergencies” created by Fanny. Snorts encourages Fanny’s reckless spending and poor decorating decisions. And since the YouTube channel exploded, all of a sudden the place is over run with the Tartan terror visiting frequently, cuz has moved in, Mummy has an apartment made for her, etc.
The 50% Shittelaine has taken over 90% of the Shittoo and Larkin feels pushed out.
Potts only owns 10% so he doesn’t care and Fanny renovated an apartment for him. But now Fanny and Potts own 60% of the Shittoo and will always stick together so Larkin is now in the minority on a property he has been responsible for 15 + years. He feels pushed out. It is no longer his home and he lost control. And he has dealt with Fanny calling him 3 times per day for years. I imagine this shitshow situation the past 2 to 3 years has put additional stress on his marriage. Fanny puts them in legal jeopardy constantly with her decisions.