A "backwoods" couple were having a baby. The man had walked to town to get the doctor. Upon returning the woman was in heavy labor so the doctor set about delivering the first child.
"It's a boy!", the doctor said, "Wait, there's another one!"
"It's a girl!", said the doctor, "I think there's another one coming!"
"Another boy!" the doctor declared!
After checking the babies and mother the doctor realized the man had not said a word.
"Well, what do you think about your family?" the doctor asked the hillbilly.
"I been a thinkin' how we got three of 'em, an' I think I figured it out." he replied.
"How is that?" the doctor said curiously.
"Well, one time we runned out o' that K-Y, an' I used 3-in-One oil. Man! I'm glad I didn't use the WD-40!"