CONTEXT.
Is it unacceptable to watch boxing because the men are shirtless?
Is it immodest to wear a wetsuit when diving because it shows the figure?
Did Michaelangelo turn the Sistine Chapel into a "brothel"?
Philistinism. If anyone sees near occasion or occasion to sin against the Sixth Commandment in watching classical ballet, perhaps the problem lies with HIM, in which case he should be averting his eyes from it, not moralising to those for whom it in an entirely innocent celebration of art and the beauty of the human form and movement that God created.
It's not just about what's an occasion of sin but about what's appropriate and decent. I would not suffer the slightest temptation watching a ballet. I just find that the poses and outfits are vulgar and immodest ... and won't watch out of principle. I call BS on your "entirely innocent celebration of ... the beauty of the human form".
Indeed, I would whitewash the Sistine chapel ceiling, or, rather sandblast it so that it can never be "restored". Michaelangelo's repugnant homoerotic art should find no place in a church. Again, it causes me no temptation ... but it's repugnant and out of place. Should I walk into a church with my butt hanging out of my pants?
St. Paul speaks about modesty of dress from the perspective of what is fitting for a temple of the Holy Spirit.
Showing up in a sweatshirt at Mass is wrong (unless it's all you have) ... not because it might cause temptations but because it is not fitting for the house of God.
Women should not watch boxing because it would be inappropriate ... whether or not they'd be "tempted".