I think your marriage is safe, as long as you can do two things.
First of all, you HAVE to wrap your head around Heisenberg’s Uncertainty Principle. Here’s the easy way to understand it: basically, the simultaneous determination of both the position and momentum of a particle each has an inherent uncertainty, the product of these being not less than a known constant.
In other words, you don’t know WHAT you’ve done wrong, and if you did know what you’d done wrong, you wouldn’t know WHEN you did it wrong.
Second of all, you have to tackle the other issue head-on. Invite the vampire over for dinner. When it’s time for desert, tell your undead guest that you’re having banana cream pie. Make a big deal about it. Say you took all day to make it, how much the werewolf you play pick-up road hockey likes your banana cream pie, and so on.
Go get the pie, and when you bring it in, pretend to trip and put the pie right in his face. Then when he’s wiping pie out of his eyes, stab him through the heart with a wooden stake. (Real wood, no Formica.)
Or you could just shoot him with kind of crossbow when he comes through the front door. (Wooden bolt, no aluminum!)