I have undertaken a fanfic 100 challenge where we claim a fandom, pairing/character/general/group, and write a fanfic for each of the 100 prompts. This prompt word was "where?"

Summary: Mike and Don ponder late into the night. Where are their lives headed?

Not explicitly turtlecest/slash. It has both Donatello and Michaelangelo, but any relationship other than brotherly is up to the readers imagination.