You can't "make" your friends do anything. If they don't or won't want to see and understand your point of view, there is nothing you can do about it. However, you can stand up for yourself if you feel they are being overbearing with their opinions, judgmental, or invasive.
Basically, you say, "I appreciate your concerns for me, but I don't feel that you are trying to see my side of things. Unless you are willing to be open-minded, this subject will be off-limits from now on. And if you continue to bark at me and judge me, we might not be friends anymore. I don't want that to happen, so please do a little reading about polyamory and ask me questions if you want to know what makes me happy."
And just because they are your friends now doesn't mean they have to stay your friends forever. Choose the people who are supportive and nurturing to be your friends, and let go of the ones that act like assholes.