is marital rape a constitutionally protected right accd. to this language?

[The Mikado]

I'm not sure that existed marital rape existed as a legal concept in Griswold's time (though it of course existed as a reality).  That said, I don't think it does mean that any more than it means that spousal abuse or spousal homicide are protected in the sacred grounds of the marital bedroom.  There's a significant difference between ridiculous and unenforceable victimless crimes like the Connecticut absurd ban on marital couples using contraceptives, or, in a more recent example of the rhetoric of privacy of bedroom relations, Lawrence v. Texas, and what you're talking about.