can you please post a pic ?
my first guess is that the skin is breaking through the clothing. Which is a regular occurrence since most characters have several meshes stacked up on each other - and you have the character to a relatively extreme move. ( not necessarily extreme, just beyond the bounds they tweaked the character to )
If that is the case, the simplest answer would be to make the section of whatever is poking through the clothing transparent with opacity maps. The even easier answer than that is adjust the pose to avoid the break through. - solutions range from....wow, that was simple, to OMG, you have got to be kidding me! lol
but i'd still have to see a pic to make sure it's not something else.
☯🐉
"To define Tao is to defile it" - Lao Tzu