There is a vid of me aggressively jerking back my foreskin, then once stretched back, I grip it and stretch it back even more. I love the sharp tugging, stinging feeling of the inner foreskin stretching and pulling away from the glans in the groove. One day, this area in the sulcus groove might tear and split. If you look closely, you can see how stretched the groove has become, also the join line is more apparent where the shaft skin joins the glans in the corona.