Middle Name Help - Husband thinks they're unnecessary

My husband thinks middle names are unnecessary but I really want to use one. So I need help convincing him.

Our girl name is Nora Bethany (Bethany is my best friend from childhood). He seems on board with this middle name (although still claims it's not necessary) so now I just need to think of a middle name for our boy name.

Our boy name is Mckay. My husband already shot down using his name (nathan) as a middle name. I think because his middle name is his dad's name and they don't get along so he's worried about naming someone after himself. I've never met my father so his name isn't an option. Any suggestions on a good middle name for Mckay? Or how to convince my husband why our children should have middle names?