Men are just naturally far more sexually aroused by seeing a woman’s bare breasts than women are by seeing a man’s chest. That’s why women going topless is far more discouraged
If women regularly went topless then men would be desensitized to it and it would be no more sexual than a topless man.
That happens in some amazonas and african areas, but it would take a lot of time to get people accostumed.
If topless women became something common, most males would do anything possible to avoid touching by accident a boob in the streets or public transportation. This would generate some funny situations.
