bump
This is the size and shape of a Penile Lymphocele. here is a little information on them:
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Lymphocele. This is a hard swelling that suddenly appears on the shaft of the penis after sex or masturbation. It happens when the lymph channels in your penis are temporarily blocked. The swelling is made up of Lymph which is a clear fluid that forms part of the body’s immune system.
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If that is what it is they take their own time to fade away, usually within a few weeks - abstaining from sex and masturbation will help it fade quicker