I can't understand one thing.
Someone here mentioned the ages of all characters here.
Sophia, Liam and Andy are 38 yrs old. So it's understandable that they were friends back in college.
But Cathy is 10 yrs younger than all three of them.
So how she ended up to be there friends?
Besides the agreeable disquisitions about Cathy's age, I think that the pleasing and youthful appearance of her character is not accidental, but rather it’s to be contrasted with the old and sloppy Neil's one, as I think that both of them should have a role in the corruption of the Parker couple. Let me explain:
Andy is an old friend of Liam's since the days when they attended the same high school in their hometown, and since meeting Cathy, Cathy has become so close with Sophia (first as Liam's girlfriend and then as his wife) that she has become a good friend of hers.
Amber is an old friend of Sophia's from the days when they attended the same college in their hometown, and since meeting Neil, Neil has become so close with Liam (first as Sophia's boyfriend and then as her husband) that he has become a good friend of his.
So, in my opinion, Neil (as the husband of her best friend) with his unkempt appearance (regardless of his age, he looks more like Liam's father than a man of the same age) and his devious behavior, could play for Sophia the role of the immoral and unwelcome flatterer to which, a beautiful middle-aged woman like her, should have already learned to oppose in order not to risk ruining two old friendships and, above all, two marriages in one fell swoop.
Cathy, on the other hand (as the future bride of his best friend), with her clean and innocent look (regardless of her age, as
Apollodore rightly pointed out, she looks like Marie's twin sister), could play for Liam the role of the young and fresh temptation to which, a middle-aged but handsome man like him, should have already learned to resist in order not to risk ruining two old friendships and, above all, two marriages in one fell swoop.
The first one (Neil) has already started to play his role (see the evening of Day 14), the second one (Cathy) I think (I hope) should start soon...
Will our heroes (the Parkers) be able to resist their malevolent influence? We'll only find out in future updates.