I need help! I am new to Sims 4/WickedWhims. My sims keep taking off their custom tops and bottoms :(

[Noxx.Official]

Just like the title says, my sims have custom bodies that I created for them in CAS. Meaning, I use Noir's top and bottom for the girl sim and then Noir bottom for the guy sim. However, any time an animation plays or anything like they, they strip that part off and then end up with the regular proportions (smaller penis, small boobs, ass looks weird and flat) It literally strips the parts I like off the sims and makes them plain looking. I am sure that because these are tops and bottoms that some nudity setting is changing it. Also, even when its not an animation or anything sometimes my girl sim will just make this woosh sound, spin in the air, then she will have tiny tits, basic stuff and no fishnets, etc. Please help. 

[Glabdo]

If you are equipping body parts in CAS, then the game is treating them like any other shirt/pants/etc. Meaning if you have "Nudity Enthusiast" enabled as a Wicked Whims trait, sims will spontaneously remove these body parts because it's treating them as a shirt/pants/etc. That's the "woosh" which is taking off your CAS item and revealing the naked body (which is likely just the default WW body).

 

To actually make your NUDE body look like the CAS part, you have to select the new mesh as your body part in the WW menu. So you're going to click on your sim, select "Wicked Whims", and then you will get some anatomy customization options where you can select other meshes to be your default body parts when naked (like a Noir nude bottom, an EVE nude top, etc). Make sure you have downloaded a version of the mesh that can be used as a default body part in WW and not just the CAS version, or it may not appear in the menu. Hope this helps.