Urine Dribbling

[tsujii]

Hi.  I'm 29, Asian, and I have had this problem with urine dribbling for 3 years.  A few minutes after urinating, my penis discharges a few drips of urine.  After learning how to milk the urethra, it has gotten less, but still happens.  I saw a couple of doctors, one of which gave me a prostate exam and urine test, and reported that all was well.  Another doctor told me that since I ride a bike all the time, things like this tend to happen.  So, i let this problem be.  (3 years)  But just last week, I have had this strange feeling (I'm not sure where it is, near prostate), where its seems like the muscles that control my urinating, kinda vibrate, or slightly twitch.  Usually happens when I'm sitting.    Not all the time, but periodically.  I am urinating more this past week as well.  Also, I am sexually active.  I assume that I ejaculate too much which caused some kind of malfuction of my prostate.  Is that possible?  Any help will be appreciated.