You don't see the need for a warning, and that's precisely why you didn't issue any warnings yourself. But if you would think about someone other than yourself, maybe you would understand that someone else would like to have that warning.

If it was advertised as an erotic or lgbt novel, then I'd say that warnings of that kind would be pointless since this type of content would precisely be what readers would seek. It would be like warning people that porn contains nudity.