There were these three nuns and they were tired of being good all of the time, so they went to the priest and asked if they could be bad for one day. He said that they could do one thing wrong but they had to come straight back and tell him what they did. 

The first nun comes back, and the priest asked, "And what did you do wrong, Sister?" 

"I spiked the fruit punch at the bingo ." 

"Very well, go drink holy water." 

The Second nun comes back shortly afterwards. 

"And what did you do wrong, Sister?" he asks again. 

"I mooned a monk, and nearly gave him a heart attack." 

"Very well, go drink holy water." 

Just then the third nun comes up to the priest and again he asks, "And what did you do wrong, Sister?" 

"I peed in the holy water."