If I were you I would be more focused on your parents, making sure that they feel comfortable facing other people. Make sure you express how much you love them and how much would you love spending time with them even in public. There is not really much you can do about those other parents - people do and will say shit. It's HS, in a couple years you're gonna get out and while hopefully still hanging out with your friends, you will have no obligation to relate to their shit parents.

I must say it is very nice of you to care after your parents like that, I'm sure they must be glad to have a son like you. You're also lucky to have friends who understand and don't mirror their parents in their shitty views.

If those other parents actively do stuff to discriminate yours, you could probably take some legal action - not you yourself, of course. You would probably have to get some assistance from an adult, but I advise you to think about YOUR parents first, because no matter if you do or don't start this, they are going to be the center of it, and even though it is for their own good, they could be really uncomfortable with it and that is understandable. And if it's just neighbours gossiping, you can't really do much about that.

I know you probably feel like your hands are tied, but hey - you've got amazing friends, you've got loving parents and you are open and comfortable with your sexuality. That's a great start to life! And people are going to talk shit all your life. Yes, absolutely go and defend yourself if they go directly after you (or your family) but let them be hateful and bitter to themselves - if they need so much hate and ignorance to be part of their lives, let them bathe in it.

Have a good day!