I thought I would share my experience as it went way better than expected.
I told them of my trip to a furry convention while they were away and at first I distanced my self from it and used dissociative words like "they" and "them" so I wasnt quite associating myself with them yet. I showed them pictures of the furry walk and told them of what sort of stuff that happened there and how much fun it was.
Mum and Dad were taking it well so I told them I had joined an Australian furry forum and had found out about the meets and stuff that happen around the place (now that I think about it they didn't question how I found out about the convention, but anyway).
And finally I told them I had started constructing a fursuit, mum even offered to get her sowing machine fixed so I can Finnish it She seemed to think it looked pretty fun although she did also say, "it looks like a good way to get bashed." (referring to going to meets in a fursuit).
Dad didn't say much but he smiled and didn't have anything negative to add. To be honest I think if he was my age he would have been a possible furry.