Of course it's fair, not fair enough, but it's a start. It's what Trump has done to his previous wives. And of course she was using him, they were all using him, just like he was using them. For crying out loud, as much money as he had, he had to marry foreigners looking for citizenship because American women wouldn't want to touch him. Melania doesn't like touching him in public.
Also, it hasn't been proven that Melania was having an affair, just that the story was going around. Regardless, if she cheated on him, fine, he cheated on her with Stormy Daniels when she was pregnant.