While your gf is being pretty cunty about this, there are things you can do to make the bedroom a more fun place to be. For example, next time she says "get a rubber" or whatever, don't. Instead, tease her, take some time to build anticipation. Make her literally beg you to go balls deep inside her. There is a time and a place to just abruptly ravage your lover and in this instance the mood was all wrong for that.
For example, when she said "let's have sex" instead of going for it right then and there you could have started kissing the back of her neck, working your way down to her pussy and tease her by moving down her inner thighs, barely flicking your tongue over her pussy as you come back up and work your way around her hips, etc. Control your pace and pay careful attention to the way she reacts to each stroke, where she responds the most strongly to each kiss, etc.
The second time around, instead of saying "let's ****" that would have been another opportune time to start at the beginning of he previous paragraph.
They see indoctrination and they call it "morality", "professionalism", or "maturity" depending on the context.