1- Often dreams will link with the lower aspects of ourselves, those parts we will not normally face in waking life.
To have obscenity- appear in a dream allows us to deal with these impulses safely; in a non-judgmental way.
2- Often obscenity is connected with our perception of ourselves.
If we are performing obscene acts, we need lo be aware of suppressed impulses.
If such acts are performed against us. we need to decide how we are being victimised in our daily lives.
3- Obscenity is sometimes associated with acts of evil.
If the dreamer identifies with this link, then he may need to be aware of his own interpretations of evil and evil-doing.