Update. Not really one to make excuses, maybe sometimes I should spare peoples feelings? A few of my friends invent elaborate stories as to why they can't make it to things that they have been invited to. Don't say you have to help your dad move house then get caught lunching at a country pub with someone else! Selfish old me, I will just say I don't want to go.
Anyway the long and the short of it is my sister has bailed on me tonight so I'm not going to the surprise party. I didn't need much persuading, I was back in my joggers within two minutes of her call.