How do I address my girlfriend’s threat to no longer date me if I keep playing video games?

A client arrives at the door today at the institute...A young and yet very successful man with the above dilema.

First, I listen to him really carefully...

Then I have the following conversation with myself first:

"I keep tripping over that one word. Allowed.

She said you wouldn't be allowed to  do something. There's something missing: agency. 

Who, exactly, will be  disallowing you? I think it's safe to say she believes it to be she.So  she said, in effect, "I will not allow you to" do it. That statement  presupposes she believes that, once the two of you are married, she will  have authority over you, and can tell you what you will and will not  do.

Starting with gaming. If you marry that woman and give up gaming at her behest, you will grant her the authority she apparently believes is her right.Do you think she'll stop there? Will she be a loving and benevolent dictator? How many of those have there been? You  have to choose whether or not to keep gaming, AND you have to choose  whether or not to continue with that woman. There are consequences to  each of those decisions and you have to be willing to live with them. I can tell you that my own mother hasn't told me I'm not allowed to do something since I was a child. Even my employers, all of them, never  told me I wasn't allowed to do a thing. They told me if I did a thing I might be let go, but the decision was mine. Nobody controls a free man  but himself. 

Allowed, she said. 

It galls  me for your sake. The cat is not allowed on the counter, the dog is not  allowed on the bed, the baby is not allowed to stick hairpins in the  outlets. You... you're old enough to seriously discuss marriage."

Me to the client: "Let's explore the word allowed..."