"Nothing yet has convinced me that DS would be more liable than DBD"
Really? You honestly think that if your DS penetrated a girl who didn't want him to, he wouldn't be more liable for that, morally or legally, than if your DBD was penetrated by a boy when she wasn't wanting him to penetrate her? Do you mean that, or is that just badly worded?
"I still thinking that telling them drunken sex is bad for both of them, in different ways, is my way forward."
Of course drunken sex is bad for them. But drunken sex is not rape or sexual assault. You need to be very clear about that and so do they. Too often, women don't seek the comfort and validation they need after rape because they write it off as "drunken sex", having been told that that's all it was, and rapists tell themselves that they had drunken sex with their victims.
There is already too much confusion between rape and sex. The distinction is not that difficult, the only people who benefit from all of us being confused about it, are rapists. That's why it's really important for us to get it clear in our heads what the difference is, so that we can make it clear to our children, so that the next generation of jurors, judges and the general public, are also clear about the distinction and don't line up with rapists by accident.