It didn't ruin the evening, but the behaviour of a lot of the audience last night was terrible.
One mobile phone going off is annoying, but it is made worse by the five minutes of rummaging and rustling that followed as half of the audience panic they've left theirs on too. And then the people talking loudly during the performance. Its rude to the rest of the audience and to the actors.
But these weren’t underprivileged teenagers on their first trip to the theatre who don't know how to behave (this is a common worry in the industry that young people are intimidated by theatre or just don’t know what is acceptable behaviour, - not something I've actually encountered myself - I think it actually sounds pretty patronising).
No, this was largely a middle-aged, middle-class audience who really should know how to behave but these are people who are so confident of their place in the world that they think their conversations are more important than the performance.