https://civitai.com/models/2133839/asymmetrical-lip-bite

Does what it says without influencing the style, unlike other LoRAs. Adding "lipstick" to your prompt will help make it more visible and is recommended for certain styles.

((l1pb1t3, lip_bite):1.2),

((uneven lower lip, asymmetrical lower lip, partial lower lip, teeth biting half of own lower lip):1.2),

blushing, half open eyes, seductive expression,

lipstick,