The joy of Before And After.
Before: she's fully clothed, in a normal situation. Could be your neighbour, your work colleague, that woman you see around town or on the train, she could be your mate's wife, your aunt, your sister or even your mum.
After: now you get to see her with her clothes off, a slave to the penis which she is giving all her attention to. Her legs are open, her mouth is stuffed full, her face is splattered with semen. You always knew she was a secret cockslave and now you have the proof.