Need advice

I broke the news to my husband today: I want to do Ironman Coeur d'Alene next June (2007). I think he's no longer speaking to me. He just kept repeating, "I knew this day was coming." ???

So: anyone out there have advice on how to convince him that this is not the terrible thing he seems to think it is?

I'm already training 16 to 20 hours a week; I wouldn't have to increase my training volume very much for the Ironman. (Of course, I would drop the volume dramatically this fall through early winter and pick up again in January.) And, since it's an early-summer race, I'd be done with my "A" race at the end of June, leaving the rest of the summer to train!

And as a compromise, I said I wouldn't train for a fall endurance event (such as a marathon).

What else can I try?