You are mistaken. The Pope is only assured by Christ that he speaks infallibly when he speaks excathedra on a matter of Catholic doctrine.
And True papal infallibility does not extend anywhere.
I am a member of the one catholic and apostolic church. If you want to call yourself a “Roman Catholic” then you have to believe the Pope cannot say “anything wrong regarding his teaching on faith and morals.” So if the Pope says adultery, and buggery are OK, then “Roman Catholics” got to believe that Jesus has changed His mind on these things and has told the Pope. Otherwise, you are not a Roman Catholic, you are a VICTOR! Read the Book!
http://www.usccb.org/bible/revelation/2
http://www.usccb.org/bible/revelation/3
http://www.whateverycatholicshouldknow.com/wecsk/pope_infallibility.htm
#891 “The Roman Pontiff... enjoys this infallibility in virtue of his office, when, as supreme pastor and teacher of all the faithful - who confirms his brethren in the faith - he proclaims by a definitive act a doctrine pertaining to faith or morals... This infallibility extends as far as the deposit of divine Revelation itself.”
#890 “The pastoral duty of the Magisterium is aimed at seeing to it that the People of God abides in the truth that liberates. To fulfill this service, Christ endowed the Church’s shepherds with the charism of infallibility in matters of faith and morals.”
#2051 “The infallibility of the Magisterium of the Pastors extends to all the elements of doctrine, including moral doctrine, without which the saving truths of the faith cannot be preserved, expounded, or observed.”