So basically in the beggining its talking about how their “love had been so strong for far too long” and we see him proposing to her. But he knew something was going to happen so “before the possibilities came true,
I took all possibility from you” is talking about how before she had a chance to mess anything up (by breaking up or saying no), he took away her chances. In a psychotic way, rips out her heart while shes alive and laughs while he does it.
He goes on to say how she was never that good in bed, even when asleep. But now that shes dead shes perfect. Hes never thought or acted like this before.
‘Cause I really always knew that my little crime
would be cold that’s why I got a heater for your thighs ‘, now why would he buy a heater for her THIGHS? Because he raped her dead body.
Then he goes on to talk about how she had his heart and how he wants to start over.
So her ghost (to repossess a body with which he’d misbehaved, meaning her own body, the body he raped) comes back from the grave to stab him fifty times and rip his heart out right before his eyes.
He realizes the wrong in what hes done but to repent for it he understands he has to do more than just die (go beyond the grave).
Then he talks of how he was in heaven while she was burning in hell to never have any rest from torment and say he’ll do anything to make it up for what he did and she says she will give her one last chance and if its not enough he’ll keep on trying to make it up.
‘Let’s have wedding, have a wedding,let’s start the killing, start the killing’ So in there they mean they’ll get married and start to kil
l for the rest of eternety. And after that we see them in a church to get married and when they do they kill everyone in the church. At the end we see them together in a photo booth so basically she forgives him after all the things he has done and become murderers together as a married couple.