Little black dot

On Saturday night I went to a friend's 40th birthday.
I had but a few pennies to spend so had assured those around me
I would be back early and in a sober condition.

Upon reaching the bar at said friend's 40th I reached into my pockets
for a $20 note to pay for my beverage.

At that point someone reached across and drew a single black dot
on my wrist. The bar tender did not take my $20 note upon eyeing this little
black dot.

And so it was....that little black dot went on to cause me a great deal of pain.
And now I need someone to hold me.

Very tightly.