Courtney is so unfair to her Dads (Obviously here there be spoilers)
Courtney claims that her primary reason for not coming out is how hard it would be on her parents (sure, sure, she also says she would be teased). She says that her dads have gotten so much crap for being gay and for adopting a daughter and she just can't bear to put the stigma on them of the possibility that she is gay because she was raised by gay men. While I agree that there would be certain people who took that view, I can't believe that he dads would care about what those people think.
She tells Hannah that the night she is going to stay over at Hannah'sis the first time she has ever lied to them. But, in reality, she lies to them by omission every day. She allows them to speculate on her partnering with various boys (specifically Marcus). I believe that they will both feel incredibly hurt when they discover that she has been this from them. That they, of all people, would understand and support her.
In terms of how the parents of the other kids will feel (with the exception of Bryce as we have no insight into their relationship since they are constantly absent) I think that Courtney's parents will take it the worst.