What do you think of an artist twerking on stage? I think it is slutty.
That's mean. Didn't you do something like that before?
I once attended a hip-hop concert, after staying there for 15 minutes, I torn off my shirt and twerked across the whole room shaking my nasty booty.
You need to be more polite if you disagree with what they are doing. Especially if you did the same thing before you need to be more understanding.
I need you to know that I don't care about your opinion.
You might not care but others will think you are a hypocrite and mean to say your opinion using those words. You can at least say it nicely and politely.