I had high hopes for this, being an Aychbourn play, but I thought it was just fine.
The story takes a little bit to get going, especially on the first read through as the characters seem to be having a number of random conversations that go nowhere. Once the two couples meet though, I did enjoy the situational comedy. Plot lines surrounding affairs and cheating are not usually my thing but Alan Ayckbourn makes it work.
I found the characters rather bland though. I think some of them would be rather fun to play because of how much you can interpret what it there to flesh them out, rather than them being fully fleshed out multidimentional characters on page.
My main issue is how dated this one feels compared to other Ayckbourn plays. Some of the references didn't make much sense to me, but if I were putting this on those could easily be changed without affecting the plot very much. My bigger issue was with some of the dated opinions, especially regarding the behaviour of the character Philip. His speach about women who wear short skirts was remarkably uncomfortable to read, etc, etc.