Congressional banking oversight is serious business, but not so serious that Sen. John Kennedy could not find a moment to slip in a hilarious quip. The Louisiana Republican was questioning the CEO’s of the largest U.S. banks on Wednesday during the Senate Banking Committee’s annual oversight hearing, according to a report by the Daily Caller. During his questioning, he asked the panel if they found it “ironic” that the Federal Deposit Inusrance Corporation was advising them on how to manage their banks with new proposed regulations despite the FDIC having watched three other banks fail this ye…