Double standard. If you can compliment a woman on her hair or eyes then nipples shouldn't be out of bounds. If they are, there you go, they'll need to be bandaided.
The alternative is that if you can see it and think about it, freedom of speech and all you should be able to talk about it as long as it isn't harassment, which it isn't if held to the same standards as a compliment about other physical attributes. If you want sexual repression in society it has to be consistent so young unevolved childrens' minds can make a distinction between what is and isn't appropriate.