If someone comes to your door and shows their private parts is it sexual harassment?

Yes.

Its also public indecency which is illegal.  If someone does that lock your door and call the police. 

it would be a stupid and potentially hazardous thing for them to do. To get to my door you need to enter a small screened in porch. IF  I open my door they will be face to face with two large dogs that will literally jump up to be face to face. Who knows where their paws will land. Plus my husband is former military. Do you have any idea how many former military personnel are armed?

They would not have their private parts attached much longer if they came to my door!