So, I've been reading X-Men for as long as I've read comics (my first ever comic was X-Men #120 - who knew I'd become such a JP fan?)
Either way, I've been reading comics for about 16 years now (I started at age 10) and have worked my way through almost every X-team comic out there.
One that that's always struck me is how gender neutral Iceman is when iced up; I mean, yes, we all know he's male, but there is never any real concern of him not meeting the PG ratings.
Running around in skimpy Speedos is one thing, but as the females wear about as much fabric as he, proportionally, I see no issues with it - I think more of him as a perpetual swimmer.
However, there is an issue of X-Men Unlimited (#9, released in August 2005) where we see an iced up Bobby with nipples.
Now, don't get me wrong, I'm not a prude. In fact, I found it rather interesting to see him iced up and showering (is it odd that I wonder if cold water gives him perky nipples? because those puppies in the second look are perkier than in the first one).
So, the question really then becomes this: Why do we see nipples?
I think there are a few options available to answer this:
1- Artist Error
Now, for whatever reason, it could simply happen that the artist forgot that when Bobby is in his ice form he has no need for nipples.
2 -Deliberate Choice by Artist
The artist could decide that since this is Unlimited and not Uncanny or X-Men proper, there could be some room to play. They may have been added as a form of Easter Egg type joke, and see if anyone was paying attention.
It may have been because the artist was pissed off at Marvel and was doing it to stick it to the admin, other artists, whatever.
it may have been an experiment. Include the high beams, see if there is a response from readers (positive, negative, neutral) and adjust the look in the other main titles from that point on.
3- Colourist's Error
If we observe a third scan from this issue, we see bandages on Bobby's back. Now, this may be because Bobby should be human and not iced, because Iceman can reform himself at any time - Iceman never really bruises or stays cut. he uses his powers to patch the injuries.
I'm not really sure which of the three options I like better... they all present something interesting (to mind at least).
Perhaps, dear readers, you have other reasons why we get treated to iced male nipples? Maybe you even know the answers. Either way, this is my take on the matter. Feel free to take the concepts and run with them.