When sims are supposed to be nude or have more revealing clothing the salmon colored (hideous btw) underwear from CAS body edit mode is showing.
Edit By Crinrict: Adjusted Title
Ideas
My sims always have tan-lines (from default underwear) after sun bathing without clothes. They get the moodlet "no tan lines", but they have tan lines, and therefor you can see them when the Sims wear some of the clothing. And that is kind of why they sunbathe nude.
same glitch for me too!
