Copyright JK Rowling.
Warning huge hints of boyxboy nothing bad though.
Borrowed
See knew way before the actual event that whenever Remus died – if of course he died before her- he would not be waiting for her to die up in heaven or whatever place lay beyond life. No she wasn't about to delude herself, Remus would always love her second best and the werewolf had been the first to admit that. Though it sounds insulting Tonks knew the truth even before Remus opened his mouth, his first and only true love would forever be one deceased Sirius Black.
At first though she wasn't so understanding as you can imagine nobody would be. At first she saw the need to compete with her dead cousin, for Remus' affections. She would try to better Sirius in any way possible, I became almost an obsession. Until the day the ex professor sat her down telling her that yes he would always love Sirius possibly more than anyone else, but that part of his life had been and gone. She was his life now, he loved her to, and she was to stop being irrational and childish.
No more was said on the subject after that, but Tonks silently promised Sirius that in whatever afterlife there was Remus would be all his.
Now that time had come, not but a few measly feet away she watched her husband, the father to her son as he was struck by the green beam of the killing curse. She silently watched him fall to ground lifeless.
Minutes later she found herself fighting for her own life, the green beams could not be avoided forever. In the blink of an eye darkness had surrounded her.
Still in darkness she decided not to look for Remus or Sirius. They could lead their own afterlives the way they wanted, together. She would not get in the way, it was time to give back what she had borrowed.
Did this work at all? Please give me feed back... XD