Rather than argue with your significant other, here are some suggestions from the Artists Network, Lori McNee.
1. Hang artwork so that the center point of the painting is at eye level for the average height person, about 60" from the floor.
2. For large pieces, use 2 hooks in the wall for stability.
3. Use"D" ring hangers on the frame and wire that will support the weight of the work. When in doubt, read the weight recommendations on the package.
4. Don't just hammer nails into the wall, use brackets or picture hooks.
5. Make sure the wire on the back of the artwork is tight enough to hide the hanger when the artwork is hanging on the wall.