While Sal and David may be passionate about righting the wrongs of the world and creating a more equal and inclusive society, when it comes to embarrassing their children it's a different matter.
The End of History, Royal Court. Photo Johan Persson.
Writer Jack Thorne and John Tiffany last worked together on the Harry Potter plays but family dynamics is the only parallel with The End of History at the Royal Court.
The play is set during three family gatherings in 1997, 2007 and 2017, in the Newbury home of Sal (Lesley Sharp) and David (David Morrissey).
They are left-leaning liberals who've brought their children up to be inquisitive and be socially aware.
Elder children Carl (Sam Swainsbury) and Polly (Kate O'Flynn) are at good universities and younger sibling Tom (Laurie Davidson) is still at school but when they come together it is a mixture of banter, jibes and warm familial bonds.
Views take their toll
Sal and David's liberal approach to parenting combined with their rigid views on social justice has taken its toll on their children.
In the first act, the gathering is to meet Carl's new girlfriend Harriet (Zoe Boyle). Behind closed doors, the kids are almost used to their parent's frank revelations and views but it is a different matter when Harriet arrives.
The fact that she comes from money is an itch that Sal, in particular, just can't help scratching with amusingly cringe-worthy consequences.