You and your sister like to play games. You both sit in a room and tell each other how to jack off, and whoever comes first has to finish the other one off with a blowjob. A lot of the time she gets carried away - even when you tell her to stop stroking,
Remember, edging to gay porn first thing in the morning will keep your mind focused on cock through out the day. Now stroke sissy. [Pro tip: wake up early and do it for several hours before work]
