The way our society explains it is that rape is OK whenever a woman is born and thereafter. At age 3, 30 or 103, she exists to be "enjoyed." Instead of accusing the rapist, we like to point out what the victim did wrong and how she could have prevented this rape. It's always the victim's fault, right? "She was asking for it." We should be ashamed of ourselves.
Rape is OK when...
... She is "showing skin," because an 8-year-old girl in her school uniform with nothing but her knobby knees showing is definitely "asking for it." A woman in a burqa with not even her wrists exposed "provoked him by her clothing." Even if a woman's skirt does not pass the finger-tip rule or if her cleavage is showing, you do not have any right to her. Her walking around in a bikini is not a secret sign that she wants you to take advantage of her. She is a beautiful human being, not an object to be used for your pleasure whether she is fully clothed or not clothed at all.
... She said "no," but she didn't mean it. Did she say "I'm just kidding, go ahead?" Because if not, she is being serious. No means no, and yes means yes. "No" is not woman code for "I don't mind." It is the same as any other no and any man's no; it means absolutely not. Even if she is giggling when she says it or if her tone does not match the word, it is still a no. A do not pass go. She is not an object to be penetrated at will, but she is a person capable of making her own decisions and whose voice should be respected.
... She didn't mind having sex last time. I see that the words "last time" were used. What about this time? You do not determine her sex schedule; you are not in control of what she does will her body. If you have had sex with her every day for the past month and she says "no" today, guess what? Her "no" is completely valid and overrides your "yes." Sex should always be consensual. Sex without consent is rape. End of story.
... She's a slut. And your point is? A "high" number of sexual partners does not equate to constant consent. By degrading her and calling her a slut and devaluing her wishes, you have dehumanized and disrespected her. Her past experiences do not mean that she cannot turn you down. You thinking you are better than the other people she has had sex with does not mean that she is obligated to do as you ask. Take her "no" as a no and move on.
... She said "yes" before you started. Consent should be given before and during sex. If she is uncomfortable, stop. If you are uncomfortable, stop. It's acceptable for you to change your mind at a restaurant, so why is it not okay for her to change her mind in bed? Why is it that your "finishing" is more important than her emotional stability? Why is it that your "getting off" is more highly valued than the pain she feels? Consent should be constant; if it is not, continuing is not an option.
... She's married to you. Marriage is not a free pass to continuous consent. It does not matter that you two signed a sheet of paper and said "I do." What does matter is that she said stop. Her being your wife should make you want to care for her even more and protect her heart even more. This includes making sure you have her permission to proceed.
Rape is OK when...
... It's not there at all. Rape is not okay in any shape or form, and we as a society need to stop victim blaming and perpetuating our rape culture. Victims should not be the ones put on trial; the rapist should be the one being grilled. Who cares what she was wearing or what she said last week? Rape is rape, and our attitude isn't helping end it.