Haha I don't know but I do too lol.
You just like being a tease. It's not a problem.
you like it because its flattering. a nice little ego boost :) you turn him on enough to make him hard.
Probably just from the fact that you can do it pretty easily whenever you want to once you know the tricks. Then once you do, you get the instant gratification sort of thing like a guy/girl making a basket in sports, a strike in bowling, or a hit or home run in a ball game, etc. Guys are at a disadvantage that way in that they can't always control the pleasure they get from visual stimulation, and mental sexual stimulation caused by a tease.
don't start a job if your not gonna finish it!