>>9649770It's probably because the victim has no idea what to fucking do. Are you going to tell some random guy from Barbados who is working security at the buffet your stepdad raped you? Especially if the attacker just does it and goes back to partying with everyone else like nothing happened and your entire family is there having a good time.. It might be days before you get a chance to be alone long enough to process what happened, much less be home and able to talk to friends or family outside of your immediate circle.
I would also guess that the general mix of alcohol, bathing suits and opportunities to isolate the victim contribute. If all it takes is two martinis and seeing your stepdaughter in a bikini to rape then you are probably pretty bent in that direction anyway though