Male, Man, Boy, Multiple characters, Caucasian, Asian, African,

Nude, Nipple, NSFW, naked, erotic,

two heads, ugly, blurry, deformed, disfigured,  jpeg artifacts,  long neck,  lowres,  morbid,  text,   watermark, haze
The negative prompts for typical skin tones such as Caucasian, Asian, African are there to stop you from getting non-blue skin tones.