I am not sure why it's a big deal to him, but I am also not sure why it's a big deal to you. And the question I think you have to ask yourself is "Is having a 'kill free zone' worth losing my husband?"

Edited to add:

And instead of just dropping the lobster into boiling water, you could try the "knife between the eyes" kill, which is more like the abattoir's treatment of cattle.