(Non CAS)Mermaids wearing a pink skirt

@mizzarrogh 

The issue you have could be a couple of things.  

I think the pink skirt is probably an unlockable clothing item that is normally hidden in CAS but I have seen those CAS items get put on NPCs from time to time and sometimes on played sims on age up.  If you can't find it in CAS, then that's probably why.

This sounds similar to the old bathing suit in the shower bug though.  It still happens from time to time for some folks and there is a mod that you can search for over at MTS that will fix it.  So I suggest you try that.

Another thing it could be is a bad piece of cc causing it.  I have had cc that was tagged incorrectly and never showed up in CAS.  If it had the random tag, it would still be used by NPCs.  So another thing you can do is take a look at your clothing cc with Sims4Studio to see if you can find if it is in the game or a cc item.  If it is a game item, it will show up under the creating clothing cc options and it will show just about everything in the game.  If it is cc, they you can look at each cc file you have to see if it is there.

If the item is a cc item, it could also be something like a hat or a piece of jewelry even though it looks like a skirt.  I had a cc male underwear that kept showing up on female sims when they took a shower.  It took me a while to find what was going on.  In the end it was underwear that was set to be a ring and was allowed to be applied to the bathing outfit. It did not show up in CAS.  Needless to say, removing the file fixed the issue for me.  You might have something similar going on.

Hope this helps.