Once the girls come back from college and are ready to start their adult lives. They've graduated and are ready to start the newest chapter in adulthood. Gabby moves back from Florida to New York however she isn't alone.
After years of being away and only costing on Holidays or whenever the girls planned something and after years of barley speaking to Raphael. Gabby meets someone new. Meet Joshua Lewis.
Joshua and Gabby met a bit after she started college. He is kind, loving, perfect. Some would say he is too good to be true.
Even the girls when they met him on a summer trip to Florida for a couple days were a little bit suspicious. Especially because the whole time he was flirting with Luci! However, Gabby didn't notice and when the girls brought it up to her. Gabby dismissed them. So they didn't bring it up again.
Fast forward to when the girls go back and Gabby moves with her boyfriend Joshua. The girls are super happy for Gabby to be back but not as thrilled to see that she brought back Joshua .
Soon enough Raph bumps into Gabby and Josh as he is in his human form going to pick up some pizzas for the lair. They are both surprised to see each other but Raph is ever more surprised when he meets Joshua. Jealous consumes him but he keeps his facade until he gets home to yell at the other girls for not letting him know until the other turtles stop him from going full Hothead and he storms off.
As time goes on, Gabby starts going to the lair more often because the girls are trying to get back into the rhythm of being a full time Kunoichi group. She and Raph begin to become good friends again. However, Raph begins to notice some red flags when Gabby talks about Josh. He is always stuck at work even on weekends. He rarely wants to go on dates. He takes out a lot of money on things but never gets her anything but since Gabby really likes him she doesn't notice all those signs.
After growing too suspicious, Raph brings up his concerns to the other girls. (After apologizing of course) and they all come up with a plan to spy on Joshua to see what he his doing. (Well raphs plan that he pleads the other girls go along with)
While spying on Joshua, they don't catch him doing anything so the other girls give up until Raph points out that he is kissing someone who isn't Gabby. That kiss turns into something more but the group quickly turns away from that and focus on what's happening. Joshua is cheating on Gabby.
After some discussion, the girls think it's best if Raph tell Gabby but sadly she doesn't believe him and gets pretty upset about it. Even after talking to the other girls about it, she doesn't believe anyone.
Which makes Raph take matters into his own hands....
After a sneaky link call, Joshua walks back to the apartment, when Raph (in human form because he isn't stupid) walks up to him warning him to not mess with Gabby or he is going to have to face the consequences with him. Joshua ignores him and the two fight. However just as Raph is about to deliver the final blow. He was stopped by his brothers and the girls other than Gabby and after making sure Joshua was still alive they all disappeared into the night. Raphael being scolded by everyone when they got back to the lair.
When Joshua gets back home to Gabby. The get into a huge relationship ending fight. Turns out the girls had gotten proof of the cheating before Raph had beaten Joshua. They sent it to Gabby and she breaks up with him sending him back to Florida.
Gabby comes into the lair to apologize to Raph for not believing him. She tells him that she broke up with Joshua and she thanks him for beating him up for her before she walks away to go train.
Even though they aren't together just yet. Raph feels hope for the first time again. There is something there and he knows it and he smiles.