This girl I'm dating bought me dinner. Did she do this to emasculate me?

No. If I had a boyfriend I would want it to be equal. He pays sometimes, I pay sometimes. I don't think it's fair to make the guy pay all the time. This is a new day and age where women want to be treated equal. If they want to be treated equal in everything else, why not be equal in who pays for dates? It's just fair. She didn't do it to insult you in any way.