I lied to my current girlfriend about hooking up with an actress from game of thrones.
Are you kidding? Why did you lie to your gf about it?
She would get mad at me and I had no intention of telling her the truth
It's wrong to lie to your gf like that. Cheating on someone is morally frowned upon.
She can mind her own business, I don't ask her to tell me what she does all day.
You know it is not the same thing. Partners are expected to not cheat on each other so when you do, you should be honest with the person. It is not going to be for your relationship to keep a huge secret like that from your partner.