What does it mean when your sacral dimple bleeds?

Pilonidal disease. Usually means that you may have had infection at the base of the dimple resulting in granulation tissue that bleeds when pressure is applied. See a surgeon. Excision can cure issue.
Needs evaluation. It is probably a pilnidaly sinus/abscess that is bleeding. It needs evaluation. It is an early sign of an infection in the hair bearing area.