One friend accidentally copied in a second when he sent an e-mail reply to say that he couldn’t make it to my birthday party – so now she knew that she hadn’t been invited. How could I explain why not without hurting her feelings?

Then, because we’d all gone out running as a crowd, SEB had managed to wheedle her way into our flat when we all came back to the house for showers. She knew that she would not be welcome, so why hadn’t she taken evasive action?