with a flyswatter in hand.
"What are you doing ?" she asks
"Hunting flies..." replies the husband
"Oh..." she says. "Killing any ?"
"Yep, three males and two females !" proudly replies the husband
"Really? ...How can you tell which are male and which are female?" is her response
"Easy" says the husband
"Three were on a beer can and the other two were on the phone..."
good one, just sent that one to my mom and her friend via email 
