I have a dark spot almost black in my butt crack. ive had it for a few months my husband thought it was a bruise (due to the color) and noticed that it still hasnt gone away. it isnt raise and it doesnt hurt its just there. irregular shape?

Any pigmented skin lesion(black/brown) with a irregular border and mix of colors can be a skin Cancer(Melanoma). I If it is bigger than the size a pencil eraser you should have a physician(PCP or a Dermatologist) examine this lesion and give you further advice. If it is changing in size and or color, a biopsy of this skin lesion would be a serious consideration to make the final definite diagnosis