Rape is rape. But illegal sexual contact is another issue.
Under current South Dakota law, sexual contact—any touching of naughty parts not amounting to rape—with someone who is physically or mentally incapacitated and cannot consent is a Class 4 felony. Sexual contact with someone who can consent but does not is a Class 1 misdemeanor. However, both clauses include spousal exceptions. You can't rape your wife, but if you're just groping, even though your wife tells you to knock it off, the police aren't getting involved.
Senator Deb Peters (R-9/Hartford) wants to change that. Her Senate Bill 120 would erase the spousal exceptions to the sexual contact statutes. Sen. Peters has newly married Senator Angie Buhl (D-15/Sioux Falls) on her side, along with a mix of Democrats and Republicans from both chambers... including the unfortunately named House Majority Leader David Lust.
The bill seems perfectly reasonable. Even in marriage, our right to bodily autonomy remains inviolate. If your wife doesn't want your hands on her, get your darn hands off.