How can I be honest..

How do you tell someone something, something that should have been told some time ago.?

Ok, for a while this has been bothering me. I want to include my partner in all of my life and Christmas! My sister bought her boyfriend to Christmas, but I couldn't cos I havent been honest with everyone. I want to stop lying to some people whilst others get the full truth-- How do I tell my nan that I'm gay? She never brings it up in conversation, I'm never drunk around her and she has never flat out asked (these are the ways that others have found out-- EVERYone else in my day to day life).

I first told my parents 10 years ago, when I was 18 years old and came out of a big depression. I was a different person back then. Still finding myself and my feet in life and it was a heaps hard thing to tell them.. But than they asked, and I just said yes-- EASY AS! Why can't it just be that easy with my nan? Also, why am I even having problems with telling her? I wanted to email her, but everyone has objected. I feel like I am being backed into a corner. Now even my partner really has big issued with her not knowing and issues with being excluded from parts of my life. Today I was asked to a work function night out and when I told him I was going just me, he got upset about being excluded from some of my life- and bought up this family issue- something that I didn't know was bothering him so much but bothers me from time to time.

So I feel slack. My aunt having cancer has also bought this issue forward in my mind as I used to feel as though I would have years to muster up the courage and be able to be happy included family, but than I realised that perhaps I don't have forever. The longer I wait, the further away it becomes. My nan is in great health, but what if she isn't around in 20 yrs time and I never told her.. How will I feel? :/ So, I'm stuck with no conclusion on how to approach this. I want to be able to include him in everything in my life, as he is worth that. Also, how slack am I going to feel with that one.. ''Heres my bf, we have been together for 3 years, I have known that I'm gay for 10 but I didn't think you would understand at all..'':/ !!! What to do. Stupid 2012, why isn't being gay just a part of life from the time you're born? Why can't guys have bfs and girls have gfs with their being any ''difference'' associated to that.