It's odd Sir, but not as odd as your wife not wanting your guns in the house.
Try talking to her about that first I would say. What is the issue? Are they going to get out of the locker at night, load themselves and shoot someone?
Does she not trust you or does she not trust herself? Seems highly irrational.
I personally would not store my property anywhere but my house. Especially firearms. I like the responsibility on me, I know me and I trust me.