so confused by mixed signals

I believe for many it's a power play - deliberately emphasizing their sexual attributes so they can berate males who show any interest. "[i]What do you think you're looking at, you pervert[/i]" It's not usually that brazen, but I have seen 2 naked females displaying themselves very ostentatiously on a public boulevard, deliberately drawing a crowd then verbally abusing male observers for looking at them.

It's a 'Gotcha' gambit. Eric Berne described the game in the 1960s and gave it the name Rapo.

@habibti Is this the reverse sexism you say is so much fun?

Of course millions of cleavage-flashing young women are not playing the game, at least consciously - just mindlessly following what has become the fashion for their gender and age group.