Two sailors on shore leave, walking down the street. They spot a
beautiful blonde. 

First sailor asks his friend "Have you ever slept with a blonde?"  

Second sailor replies that he has. 

They walk on further and see an even more beautiful brunette. 

FS, " Have you ever slept with a brunette?" 

SS, "Why yes, in fact I've slept with brunettes on many occasions" 

They walk on a little further, and see a gorgeous redhead, who leaves
the other two girls for dead. 

FS, "Have you ever slept with a redhead then?" 

His companion looks at him and replies "Not a wink!"