Two priests - Pretty Funny!

Two 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 had 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 blonde in a thong bikini came walking straight towards them. They couldn't help but stare. As the blonde passed them, she smiled and said, "Good morning, Father, good morning, Father," nodding and addressing each of them individually, then 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. 
Once again, the two priests settled on the beach in their chairs to enjoy the sunshine. After a while, the same gorgeous topless blonde, wearing a string, taking her sweet time, came walking towards them.
Again, she nodded at each of them, said, "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?" she asked."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 Angela."