I wonder what it is Hannity is hiding.
Well, we already know that he was hiding that Cohen was his lawyer. Which by itself is bad because Hannity has been talking about news concerning Cohen without disclosing his connection to him. This is a severe ethical violation.
...But the fun part is that unless he was just being shady for the sake of being shady there must be something worse behind this.
Did Cohen pay off some mistresses or prostitutes to keep their mouths shut about Hannity? Well, that's a personal issue between Hannity and his wife and the least bad scenario for him.
Did Cohen act as a go-between for Trump and Hannity? That could be another ethical breach if Hannity has been doing PR work for Trump administration while getting paid to do so (while we've just been thinking that he defends Trump and spouts Set Rich conspiracies simply because he supports Trump) and maybe it's even illegal, not sure about the laws in USA concerning these kinds of matters.
All we know is that IF something illegal happened, the evidence is now in FBI hands and Hannity is in trouble. If on the other hand this was merely ethically questionable and not illegal then he could have avoided all of this by mentioning early on "BTW, Mr. Cohen is also MY lawyer, but now back to this story about how FBI is unlawfully harassing the president's lawyer."
It's just that it seems silly to me if the bigger scandal is that Hannity didn't reveal his connection while trying to discredit the investigation rather than what the investigation actually can uncover about him...