Help Rigging Lips Please!

I am trying to skin a character I made… Everything looks good but the lips. When I give a lip bone full influence of the vertices that correspond to it it freaks out… anyone know why?..

would more than appreciate the help. :slightly_smiling_face:

The lips look thin, indicating diffuse weights. The crease on the right side of the pic suggests a bone that’s getting a strong roll. People would probably need to see the rig and the base mesh to offer more info.