So, a guy is stranded on an island with only a Doberman and a pig 
for company: 

     There's plenty of food and water, and the weather is beautiful, so 
he's doing alright--but after a few months he gets "lonely", if you know 
what I mean! 
     
     The pig starts to look more and more attractive--soft, pink flesh, 
round buttocks, etc. But every time this poor guy makes an advance towards 
the pig, the Doberman snarls at him and once almost bit his leg. Very
frustrating.
 
     One day the guy sees a speck on the horizon, so he swims out there 
and it turns out to be a dinghy, cast adrift, and in the bottom of the 
boat is a beautiful woman, unconscious. He drags her to shore and brings 
her into his hut and slowly nurses her back to health. 

     Finally she is well enough to walk and she says to him "Thank you, 
thank you for saving my life. I don't know how I can ever repay you. 
I'll do anything for you, anything, just name it." The guy thinks for a 
minute and says "Would you mind taking my dog for a walk?"