It is the The law of Allah. If he does haram and four witnesses so and he doesn't get lashed, You know he will go to Jahannam or Hellfire, You don't what your Brother to be in the worst place.
Why would 4 people watch two people making love? Is it for reporting purposes as witnesses? Yes, judge, he lifted he dirac, she said wait, put on this plastic, but he hesitated.........bla bla...bla bla....documented the whole thing for a future court case?
Op
A woman is in charge of her body, if she wants to get rid of her foetus, so be it. If Gods, the prophets, scholars, rulers and the judges were females, they would have legitimised abortion.