If a female becomes President, will that make her husband the first First Man?

The First Gentleman i think.

First Gentleman would maybe be closest equivalent

Yup.. that’s how it goes.. guess so...

yep.

here's a snippet from a site:

If a male president's wife is the first lady, what would a female president's ... a "First Gentleman," and what his functions, rather than the usual what her functions, ...

If she is married and married to a man her spouse would likely be the first gentleman. Ladies and Gentlemen is a form of honorific.

www..com/wp-dyn/content/washingtonpostarticle/2008/01/08/AR2008010804309.html

First Gent

I would think so

Im adamed if I know...

Well it isn't called First Woman now it is First Lady, maybe First Gentleman would be the equivalent.