Learning to ride a dirt bike expertly goes a long ways towards safety on a street bike. Stay away from the "crotch rockets" (cafe racers) even though they are cheaper. I first learned to ride on a dirt bike and those skills save me from serious injury twice.
Tell her the truth and ask her to teach you. Trust me, that will be a lot of fun if you just man up to what you don't know. You might learn a lot more that way than if you try and fake your way through it.
Only if it is interfering in life functions.. which indicates an addiction. Although twice a day does seem excessive. The discussion shouldn't be about porn but about whether it is an addiction.