A nun was walking in the convent when one of the priests noticed she was gaining a little weight.
"Gaining a little weight are we sister Susan?" He asked.
"No, Father. Just a little gas," Sister Susan explained.
A month or so later the priest noticed that she had gained even more weight. "Gaining some weight are we Sister Susan?" he asked again.
"Oh no, Father. Just a little gas," she replied again.
A couple of months later the priest noticed Sister Susan pushing a baby carriage around the convent. He leaned over and looked in the carriage and said, "Cute little fart."