I agree with Zelhar.
Also, most societies have standards of modesty. So his statement that non-Jews could technically "run around naked" is completely wrong. Pre-marital sex is also frowned upon in most societies (at least for women). It's not just a Jewish thing.
Now on another note, I'd like to know what this conservative girl was doing in a beauty pageant. Parading around in scanty attire to be inspected by judges is NOT modest, in my opinion. I don't understand the appeal of these pageants for young girls. The attractiveness of a woman should be between herself and her boyfriend/husband.