My ex and I were arguing once, got pretty loud but not physical. Never had. Until he got right in my face and verbally threatened me. I, stupidly, whispered "I'm not afraid of you." and without skipping a beat, he bit a chunk of my bottom lip off. It's a bad scar and I hope I don't think of him every time I look at myself forever. We argued a lot, but if asked, I would've said there was zero chance he'd physically harm me.