Custom Underwear doesn't work (LE)

[i0brendan0 2]

Hey, so I'm trying to make a custom piece of armor so I can just go around in just underwear. I'm having a major problem with it and I have no clue how to fix it. Basically what happens is, sometimes it'll show the underwear correctly. Other times, the underwear goes away and then there's no genitals.  I originally used the naked body mesh that came with SAM and then switched to something from the vanilla revealing mod to see if it would fix it but I had no luck. I'm completely at a loss. I thought there were some guides out there that I could use to resolve this but I can't seem to find them anymore.
 
I'm hoping there's something super obvious I'm doing wrong that someone might just be able to throw out the fix for, but if not, I can provide my plugin. I'm pretty much using the standard SAM naked body. Thanks.