Bikinis literally make men view women as objects.

I, for one, am a gentleman and would like to buy these objects dinner first. From National Geographic:

Sexy women in bikinis really do inspire some men to see them as objects, according to a new study of male behavior. Brain scans revealed that when men are shown pictures of scantily clad women, the region of the brain associated with tool use lights up.

Men were also more likely to associate images of sexualized women with first-person action verbs such as "I push, I grasp, I handle," said lead researcher Susan Fiske, a psychologist at Princeton University.

And in a "shocking" finding, Fiske noted, some of the men studied showed no activity in the part of the brain that usually responds when a person ponders another's intentions.

This means that these men see women "as sexually inviting, but they are not thinking about their minds," Fiske said. "The lack of activation in this social cognition area is really odd, because it hardly ever happens."

[...] And the men who scored higher as "hostile sexists"—those who view women as controlling and invaders of male space—didn't show brain activity that indicates they saw the women in bikinis as humans with thoughts and intentions.

Scientists have seen this absence of activation only once before, in a study where people were shown off-putting photographs of homeless people and drug addicts.