Your relationship hadn't always been toxic. It started off light, that familiar puppy love at having a crush. The subtle flirting, the banter, the butterflies; things had changed drastically within the course of a few months. 

He'd get in your face, sometimes raise his voice, or he'd take that condescending tone that hinted at you being nothing more than a a pet. Donatello himself thinks he's always in the right, never takes responsibility for anything. 

But he'd be damned if he let you go to anyone else. He'd yank you by your hand the second you try going out the door. Scolding you as if you're some child that doesn't know the dangers of the world. Guilt tripping you on how you never want to spend time with him, how you prefer your friends over him, how he can't begin to understand you. 

But then he holds you close and whispers affection into your ear. Because he can never let you leave him, and outright refuses to let you even think of doing so.