It is always good to get some clarity as my initial reaction is always to respond but I held out this time.
As it was to do with S16 I text him back 'yes, plan is fine' without any emotion etc. This is very different to previous texts where I have include niceties to him. I hope the text was cordial and not too business like.
He hasn't returned any more text so he is obviously content with this as am I.
