DS (3.5y) is intact and recently he's been saying that his penis hurts when he has an erection. I think what's happening is that he's trying to pull his foreskin back and it won't slide back over the glans. He's able to get it about halfway over the glans and then says that it hurts. It looks to me like the foreskin opening literally isn't wide enough to allow the entire glans to come out.
Is this normal?