If the Constitution is subject to cultural norms (how else to you explain the Texas ruling?), then why wouldn't it also be subject to international influences? Thomas' dissent said they did read cultural norms into the ruling and I don't see how anyone can deny that. On what else was the decision based? Certainly not on the U.S. Constitution! I see no right to sodomy in the Constitution. Do you? Do you deny that ideology/culture influenced that ruling on Texas?
Do I agree that the Court mentioned cultural norms? Yes. Do I agree that they relied on them as THE basis for the decision? No.
(Pulling on Nomex hood and suit) Do I see a right to sodomy in the Constitution? Not exactly. But I do see an inherent right to be left the hell alone by the government. And anyone who wants the state to outlaw homosexual sex better be prepared to have the state outlaw getting oral pleasure from your wife, because the historical basis for the two is exactly the same. In fact, most legal definitions of "sodomy" include both. And, as far as the 9th Amendment is concerned, I am hard-pressed to come up with a more inherent right, which would be retained by the people, than the right to choose which place you stick it in - as long as the owner of that place is willing.