ST. PETERSBURG — Attorney General Jeff Sessions’ response visibly frustrated several of his former fellow senators, who felt he had no right to decline to answer them.

He insisted he had the right to respect the president's right to invoke executive privilege. But is that true?

Executive privilege is something only President Trump can invoke, and he hasn't.

It's the ability for the executive branch to block sharing information with Congress or investigators - with some exceptions.

Sessions did not take 5th Ammendment, his right to not incriminate himself.

He did not claim national security was a reason for not answering questions.

He is simply saying that his conversations with President Trump - about anything - are privileged.

We honestly don't know whether they are legally privileged.

Sessions is offering no further explanation.

But a constitutional law expert I spoke with says in Tuesday’s committee, Sessions could choose to answer -- and not answer -- what he liked no matter what.

“Being under oath and being compelled to answer the question are different things. (Sessions) could just leave. (He) could just get up and walk out. (He’s) not required to be there. So that's the difference between a subpoena and voluntary testimony. (He’s) not required to answer anything legally,” said Stetson Constitutional Law Professor Louis Virelli.

We are likely not going to get many real answers from members of the Trump administration until subpoenas are involved.

Legal experts say more likely than not, that could come from special counsel Robert Mueller's Russia investigation, and not the ones going on in Congress.