some say that all the characters that appear in a dream are aspects of the dreamer - your subconscious may have picked this aquaintance out merely for conveinience. is there an aspect of yourself that you are unhappy with, want 'got rid of? i once had a dream that i was a man and had 'relations' with a woman(also me), who then was shot by her other lover (me) as me the man erm... well reached the summit with the woman (me) ... it was at a time when i wondered if i was acting like a complete turnip in a relationship and this sort of confirmed it for me... so i stopped doing it. Hoorah!
anyway. it was a great dream, and i'm not that worried if my theory is balls -
one last quest - did you feel anxious when you woke? relieved?