Brother's Gay Too...

4 years ago I came out to my parents. My very religious, conservative parents. They took it very hard, hardly speaking to me for weeks (I had already moved out of the house). To this day, it's a very sore subject, and my mother basically refuses to believe it ("/u/NovaNewbie2016, have you been seeing any girls lately?" etc.) I have to remind her that no, I'm gay, and that her denying it is only making things worse.Well, two nights ago, my little brother called me and came out to me. He's 17, still in high school, still living at home. He's a football stud at his school, very popular, all that. A lot of his friends know, and they couldn't care less. But he wants to tell my parents now. If they struggled with their oldest being gay, when I wasn't this picture of the "perfect straight boy" like my brother is, how will they take it when HE tells them? He said he hasn't decided if he definitely is telling them, but wants to.What should he (and I) do? I know that inevitably the parents will blame me for this.