I'm definitely thinking the "will you ever love again part" and the "another boy without a sharper knife" part go hand in hand. Like, shes cheated or moved on, but the new guy hurt her, yet didn't quite break her heart (kill her). So the chick goes back to the original, and they try to make it work, and he goes back and harms the second guy who hurt the girl. But, the original is always worried shes gonna leave again, so he suffocates her with his affection. And theyre always together cuzza the ring and all, but shes slowly dying (suffocation) and he's always in denial about her being a "stranger" next to him.