I have a dark spot in between my abs (vertically) a darker shade than my skin, like dirt. What Is it ?

Its also under my chin


I rub on and get the eraser residue type, but its dirt i think


How do I get rid of it?
I have a dark spot in between my abs (vertically) a darker shade than my skin, like dirt. What Is it ?
either take a really REALLY long bubble bath (psst. i have one too!) or you can accept them as birth marks. sometimes birth marks dont appear until your later years.