Dyspareunia is pain during intercourse.
Pain with guys is often caused by a frenulum that is too short or a foreskin that’s too tight, by a penis that is too crooked, by an oversensitive glans or by an infection.
Girls can feel pain if they start intercourse before they are aroused, their vagina being too dry. Other possible causes are a tough hymen, a vaginal infection, an involuntary tightening of the muscles around the vagina, vulvar vestibulitis or kamsymfyse. Pain in the abdomen may be caused by PID. If a guy goes into the vagina to deep to fast he’ll hit the cervix, which may also be painful.
Sometimes it’s hard to find out what causes the pain, even for a doctor.
If intercourse is painful for you or your lover don’t continue as if nothing is wrong or as if it will disappear by itself in due time. This might well destroy your (sexual) relationship. Stop having intercourse, make love in other ways by using your hand(s) and/or mouth and seek medical help to find out what’s wrong.