Their family of origin was shared, they came from the same tree, maybe not the exact same branch, but it was not too far off.  They spent their childhood together, sharing everything, to a point where they seemed twins.

Years passed and their affections only grew, but they kept their love platonic, neither knew why.

yet that changed on a cold winter night when play turned into rubbing, rubbing into grinding and all that friction was starting to create sparks between them.

until the fateful moment when the fire of passion ignited. Time flew by in the heat of the heat of each others presence, but it didn't last, soon the fire withered, and not long after died.

But then again, matches aren't made to last.