cog - Thanks for the tips but I haven't said anything yet about how I will present the letter apart from reasuring Loz that it will be as kindly as possible. I am not feeling anger about it at all. I have been out for 17 years. I am not talking about adressing an acute sutuation. If I do nothing then in another 17 years either me or my parents or both will be gone so if allowing them to behave this way unchallenged isn't going to change anything then why not just say what I'm thinking?
Dagney - Its a good question. I don't know if they seriously think that shunning might make me want to go back but that is what they are taught to think isn't it?
Darth - I'm not a fader.
Thanks for all the feedback so far. I am still in 2 minds about it and appreciate your thoughts.