Partisans may object "but in the abortion case it is objectively extending inward and the other perspective is the optical illusion". But that objectivity is a moral illusion.
i personally agree with the recent supreme court ruling that abortion rights shouldn't rest on privacy protections, but rather on a robust reading of the constitution that bodily autonomy is a fundamental right above and beyond states' interests (nation state or US state). i'd extend this to the issues of euthanasia and suicide as well. the state should have a very narrow and rigorously limited set of concerns (foreign relations and interstate disputes, in the case of the US federal govt).
It seems specious to claim this when the states' interests in the body in this regard (as well as gay marriage and any other rights formerly predicated on the right to privacy asserted in Roe) are based on conservative Christian beliefs and mores.
gay marriage shouldn't be predicated on privacy either. two people want equal protection under the law as any other two people who have enjoined their lives together. that's basically it. certainly the gender/sex of those two people isn't the state's concern, because reproduction is not a state concern, but rather a private matter.
Supreme Court just made it state one, instead of keeping the decision on doctors and pregnants.