When should I tell my parents I'm getting married?

I'm getting married on Dec 23rd and my parents don't know yet. My FH is in basic training for the air force. Last week he wrote me a really romantic letter asking me to marry him when he comes home for Christmas. I want to tell my parents soon, but I also don't want him to be upset that he couldn't be there. Plus if I tell my parents, they'll most certainly tell his parents and I don't want to take that away from him. Should I wait until he gets out in 2 weeks then we can each tell our parents? Or should I tell mine, but make sure they can't tell his?