TMNT FANFIC: A curious brotherhood

Human AU

Leo never expected to be a father, son and brother to Raph. But on strange turn of events, his whole life is turned upside down.
After his ability to age was taken away and Raph had been forced back to infancy, things become more of a challenge.
And Withought his other two brothers to help keep his rumbustious child in line, Leo has to raise his former brother alone. But after all the effort and sacrifices Leo has made, will Raph ever fully appreciate everything Leo has done for him.
Will he too make a good father, when given the opportunity?
His ex never thought so.