The point I'm making is that you only take issue if the parents are gay specifically. I am saying parents are parents regardless of sexuality. Neither is beholden to being warned about anywhere. The description doesn't need to be "more transparent" in that fashion. The strange thing here, is that you do not seem to realize how homophobic your "advice" is. If one would not notify about straight parents, one would not notify about gay parents either.
The story isn't even about the MC's parents, they're a supporting role. There is no content to even warn about, it's a non-issue that you have a problem with due to prejudice. Your "advice" is not reasonable, it's bigoted and therefore unwarranted and unwanted.