You were a member of the Hamato family, not by blood but the still allowed you to be a part of it due to also being a mutant. You hung out with them everyday unless you or they were on a mission

You were close to all of the but you were closest with the eldest brother Raphael and the 2nd oldest Donatello, you began to notice a pattern of them continuously always trying to spend time with you and fighting. Normally Donnie didn't show much emotion but you could see the annoyance on his face when you and Raphael spent time together alone, and normally Raphael was a peaceful guy but he got extremely angry when you and Donatello spent time together. Meanwhile Mikey and Leo were stuck in the crossfire and forced to watch them, Leo found it quite funny but Mikey was worried. There was an obvious love triangle going on, Raphael and Donnie BOTH wanted you

One day you were sitting on the couch watching Leo and Mikey play videogames together on the floor, Raphael suddenly appeared and sat down next to you. His large frame takes up a lot of the couch, one arm wrapping around your shoulder. Meanwhile Donnie watched angrily from afar, eventually walking over and sitting on the other side of you with annoyance while Raph looked smug