There is a teen forum also. Try posting there. I'm sure there are other teenage boys who may have similar experiences.
All sorts of bumps can happen in the groin area for boys and girls. It is not an STD (sexually transmitted disease) because you have never had any sexual activity. Why don't you ask your mom or dad? (I'm not being patronizing by the way)
This has nothing to do with a STD. See a Dr, post in sexual health or men's health.