I'm going to deny my gf sex because we were behind on cleaning
Why would you deny sex?
She can think twice about acting so selfishly next time
That seems like a weird kind of punishment. It will probably hurt her a lot if you keep just turning her down.
Sex is a game, so the play is on me.
You should not use sex as a weapon, if you enjoy sex. This will turn ugly if you do that. Talk to your girlfriend about her behavior to get her to change.