i like how you assume he isn’t teaching his boys to be decent people

He was responding to a post about bad male behavior by saying "And that's why I warn women" instead of "And that's why I taught my sons about consent, etc." If he actually did the latter, it was more germane to lead with it.

where did she assume that?

We’re assuming that because the conversation is about poor behavior in men and instead of telling us how he’s raising his boys to be better he told us about how he’s warming girls. We actually learn a lot about someone based upon what information they give and what they leave out.

Go play Skyrim