My husband has been getting a sudden severe headache right after ejaculation. I'm insulted. Why?

It can be prevented. No need to get insulted - it is nothing personal. Orgasmic headaches are quite common and can be prevented by taking 2 migralex or 2 advil (ibuprofen) 30 minutes before intercourse. Your husband doesn't need to do it for long - after a few weeks he try to have sex without the medications. Other preventive measures: regular aerobic exercise, taking magnesium daily, avoiding alcohol before sex.