It was so inappropriate when Ridge went into Caroline's bed while she was passed out drunk and then proceeded to have penetrative sex with her while she thought it was her husband - Thorne. They later sort of re-wrote it to Caroline telling Ridge that she... "sensed" that it was Ridge at some point during the act and allowed it to happen. But in the initial phase of the storyline... Caroline was shocked to discover she did not sleep with her husband Thorne.
Then the final disgusting storyline element was when this disgusting thing... confirmed to Caroline that she wants Ridge and only Ridge and she can't have sex with her husband again.
So... this was basically a romanticized rape.