Let me just say that on a Carnival cruise to Ensenada we took some years back, during College Spring Break time (We know never to do THAT again!) I would've been very happy if the young women in the dance club had simply kept their sexy clothing ON.
No lie: I saw at least two young women with halter style dresses, on the dance floor, reach up to the back of their neck, untie the halter and drop the front of their dresses, and danced topless until it looked as if someone from the ship crew might see them, then they would tie them back up, only to come back down when it looked like it was "just passengers" again.
My husband and I just left the dance club (okay, he may have wished to have lingered, but he didn't SAY so! ;o) )....I thought it was bad enough that these young women were, IMO, putting themselves in harm's way, but at the very least they might have thought of the other passengers who had not expected a topless bar on the cruise ship.
Topless belongs on the sun deck, not in the dance club/lounge in the public areas of the ship.