If you have been letting a spider live in your house, and your spouse kills it...
Is that any worse than having a pet like a dog living in your house and your spouse killing that?
What if they never approved of the pet in the first place?
Does it matter if its a caged spider (like a tarantula that perhaps escaped its confines) or a daddy long legs hanging out by the back door?
Does it matter if your spouse knew it was your pet, or not?