My step brother has always been a big part of my life (from childhood) as has his sister. After many years of separate lives and nights out getting fewer and fewer we had a fall out earlier this year. I argued with his sister about a small matter and he leapt to her defence rather too vehemently. We patched it up, sort of, a few months ago but things have been strained. It's his 40th in October and he's invited DH & I, my brother & sister, his sister. Trouble is its in Kent (his new home with new partner), kid-free & DH & I can't do night away (we're in London, as he is at the moment). Would we go? Will this look like cowardice or sour grapes? The final snub?