The first point to be made in answering your question is that your husband must visit his GP and have this matter assessed. There are many causes for passing blood from the penis but the fact that it is happening after intercourse suggests that the source of the blood could be the urethra, prostate or the seminal vesicles. It is also possible that the blood is coming from his bladder. Your husband needs to have his prostate examined as part of a comprehensive genitourinary assessment. It is likely that he will require referral to a urologist for specialist assessment. Passing blood like this can never be considered normal and should not be ignored.