Custard TroutAurora Moon
Never said that you couldn't use rape as an story element… just that I would get offended by rape. ;)
So, you don't get offended by rape, but you also do? What?
The question for whether or not it's “offensive” or just “shocking” is based on how the rape is presented. Is it portrayed as a violent act that wracks the victim with rage and shame? Then it's part of a story element. Is it an excuse for the female lead to have all her clothes torn off and have her boobies get all jiggly while some guy has his way with her? Then that's pointless exploitation and it's offensive.
Basically anything will have a realistic way to do things and a “sexy” way to do things. Whether it's as simple as a perfectly normal activity being done from a “booty shot” perspective, or the female character going out of her way to thrust her chest forward when opening a door.
In most cases sexifying things isn't offensive. A bit crude, perhaps, but I can tell you firsthand it makes a lot of situations more fun to draw.