Is it normal to be turned on when I see other men checking out my wife??

Normal: What the majority does

I'd argue norms differ depending where you are from and that they change through time, so it's in flux and dependent on your community. Also the things considered normal are the things most people are comfortable in sharing, so if it's a commonly held thought/opinion/etc. that people aren't comfortable in sharing you'd never know it's normal.

@Liebik: Well normal has different levels by country by region by culture and also by as you said community but things like Male and female are normal. Meanwhile how you wear your hat or do you tip? not so much