If it hurts to turn over the foreskin, it means that the opening of the foreskin is relatively small, which will cause pain. It is recommended to turn over the foreskin frequently, so that the opening of the foreskin will slowly become looser and will not be painful after turning over. If the foreskin is wrapped around the glans for a long time, it will easily lead to glansitis and the accumulation of foreskin scale, which may induce penile cancer. You should flip the foreskin and clean it every day to avoid pain during sexual intercourse or premature ejaculation due to high sensitivity of the glans, which may also lead to vaginitis during sexual intercourse due to lack of hygiene, and long-term vaginitis may induce cervical cancer in women.