Priests on holiday

Two Catholic priests decided to go to Hawaii on
  vacation. They were determined to make this a real
  vacation by not wearing anything that would
  identify them as clergy. As soon as the plane landed
  they headed for a store and bought some really
  outrageous shorts, shirts, sandals, sunglasses, etc.

  The next morning they went to the beach dressed in
  their "tourist" garb. They were sitting on beach
  chairs, enjoying a drink, the sunshine and the
  scenery, when a "drop dead gorgeous" topless blond in
  a thong bikini came walking straight towards them.
  They couldn't help but stare. As the
  blond passed them she smiled and said "Good morning
  Father. Good morning Father," nodding and addressing
  each of them individually, then she passed on by.

  They were both stunned. How in the world did she know
  they were priests? So the next day, they went back to
  the store and bought even more outrageous outfits.
  These were so loud you could hear them before you even
  saw them! Once again, in their new attire, they
  settled on the beach in their chairs to enjoy the sunshine.

  After a while, the same gorgeous topless blond,
  wearing a string, taking her sweet time, came walking
  toward them. Again she nodded at each of
  them, said "Good morning, Father. Good morning,
  Father" and started to walk away. One of the priests
  couldn't stand it any longer and said, "Just a minute
  young lady."

  "Yes, Father?"

  "We are priests and proud of it, but I have to know,
  how in the world did you know we are priests, dressed
  as we are?"

  "Father, it's me, Sister Katherine," she replied