Pimples on ....or are they?

Since you shaved the area it is probably an ingrown hair. Your description indicates that it is infected. The intelligent thing to do is visit a physician. If the infection goes unchecked it can become quite painful and do serious damage to the equipment. If the "cap" is disrupted during your partner can become infected. You needn't worry that the physician will be overly curious about how it happened, nor will he/she tease you. They deal with this sort of thing rather routinely. You won't be his/her first case of this sort. If you are a teenager living at home, you'll find your parents will be accepting of the situation.