I'm going to ghost my girlfriend
Why would you ghost your girlfriend?
I don't want to hurt her feelings? I'm such a coward
You shouldn't be a coward. It's important to talk to your partner about problems instead of ignoring them. If you ignore her then she will confront you about it angrily.
I don't think it's that bad to ghost someone.
It's very frowned upon to ghost people, much less your girlfriend.