Hairbrush ... not a problem although it doesn't happen real often.

Toothbrush ... not sure that we ever have, but I don't have a problem.

Deodorant ... probably the fragrance discourages cross-use more than anything else. She probably doesn't care for Old Spice and I'm not big on the scent of flowers.

Actually, I consider everything I have as being "ours" and if she wants to use anything ... not a problem. I guess I took that "two become one" thing pretty seriously!