I was setting up doubles with a young lady I have seen recently and some questions came up.  I was agreeable to the price that was quoted for the amount of time but my question to her was will I get the full half hour/hour, or will it be one and done?   Her answer was one and done.  

  On a related note, Smilingbill12 did a great review 
http://eccie.net/showthread.php?t=723749 on doubles that raised some similar issues.  
Doubles has been a fantasy of mine for quite a while, probably true for many guys.  My question is what is the standard (if there is a standard) protocol for doubles?  Is there girl on girl play?  Is switching off allowed?  One and done or the time period?