Re: Problem with muscle that ejaculates/amount
An inflammation or infection in the prostate gland can produce those symptoms, or similar ones. Small amounts of blood may appear in the urine and/or semen, and the amount of semen ejaculated may be reduced, as well as the force of the ejaculation. If the inflammation or infection is substantial, the penis itself may feel somewhat sore (due to what is sometimes called "referred" pain or discomfort) , and the sensations of orgasm may be affected, although the actual infection is not connected with the head of the penis where orgasm takes place.
This condition can be cleared up by prescription medication, usually an antibiotic. See a doctor or urologist. Good luck!