I have a stinging sensation in my penis after I workout and then masturbate (Read Carefully)?

Hi, Im 14 years old and after I workout then masturbate I feel a mildly unpleasent stinging sensation in my groin area but mainly in my penis and the lower shaft of my penis, I have no clue why. I masturbate regularly as most teens do! I masturbate at least once a day and on weekends 3 times a day NOTE: When I masturbate normally without doing a workout before, There is no stinging pain it is only after a workout and then masturbate. It stays with me for a good 10, 15, 20 minutes, not sure what it is but most of my friends get this as well, I would appreciate any help from anyone who can give me it thank you!