Okay, here's a new render with some tweaks that - I think - address both the SSS and lip issues.

@ghostship2:

My Poser build is 13.1.449, the first publicly available P13 build. Because, you know, I'm just an ordinary person, not someone fancy. :-) In P12 and P13.0, I'd been using the "Walk" mode for SSS on a PhysicalSurface node, which got results I was happy with. Now after switching to P13.1, I suddenly saw weird bluish shadows with that. I tried Burley instead and also dialed down the SSS amount, which made for a better-looking image, but had the typical Burley glow. Now the below is "Walk Fixed", also with a reduced overall amount, and I'm quite happy with that now.

@RAMWorks:  I don't think it's the mask, but since the lips are a separate UV island from the head (thanks MikeJ :grin:), it's possible that there's a slight mismatch between the "head" and "lips" skin in the texture map. In the image below, I've darkened the lip skin a bit, which I think does a decent job of reducing the light outline. As I said earlier, there's also probably some extra light caught by the edge of the lip that makes it brighter, so personally I'd be happy to leave in a slight outline like here, but that's a matter of taste.

-- I'm not mad at you, just Westphalian.