I know that some people don't like the "coming out as gay" comparison. I'll use it anyway because it's really a very useful parallel, so tough nuts.
I once talked to a gay guy from the state of Washington. His family were obviously extremely liberal Christians, and his mother already knew and was "whatever" about it. His father sounded like more of a flaming pinko commie than his mother. The boy had also had a very impressive track record of being able to tell people in his life that he was gay and get a very "whatever, yeah-and-I'm-really-a-redhead-beneath-this-blonde," sort of reaction. He was still insecure about telling his father, though. I told him basically to quit being stupid, and come all the way out. His dad actually took it better than anyone so far.
Other people I have talked to had very nice parents who were also from a more traditional background. What I tell them is that their parents obviously love them and are very nice people, and there is no need to upset them. I tell them that they ought to wait until they have a steady partner they can depend on and more maturity, so they will be better prepared to handle their parents' reaction. If they are teenagers, I tell them, "you may think you won't do this, but you are young: if your parents reject you for this, you will get angry. You will say things that you don't mean. When you are older, you will have the maturity and sensibility to smooth things over. For heaven's sake, wait for just a little while longer. You only have two more years before you can manage on your own if you have to."
Only you can decide whether or not your family are the types of people who can understand something like this. If they have consistently chastised you for doing anything that they regard as "childish" or "stupid," do you really expect this to be any different? If they have a history of being harshly critical and nasty over anything about you that they didn't instill into you, do you expect this to be any different? If your parents are the least freethinking people in the universe, do you really think that you are going to change them?
You are not stupid. I do not give you permission to be stupid. You can figure this out for yourself. If your people are truly freethinking and fun-loving people who would probably embrace this about you, you will be able to tell. Some people are lucky. I know some kids whose parents actually take them to conventions, and the parents have more fun than their kids! I'm not kidding! The only regret they ever have is if their parents end up being more into it than they are, and they find it kind of embarrassing.
Just don't try to force your parents to be that way. You don't have a right to change them. You should do what you wish they would do for you: love them for who they are. If they are stodgy, conservative Christians, love them FOR that, not just in spite of it, even if you disagree with those beliefs. Maybe, if you learn to show them this kind of love, they will learn to reciprocate someday. You are the one who has to learn this very adult perspective, though.