Forgetting to Return the Favor
Stage of the relationship: Every stage
If you want to be known as "that sexually selfish dude," act as though her orgasming is completely irrelevant and nothing more than an afterthought in your mind. Seriously though, why do you have a monopoly on pleasure?
If there's a chapter in the Penis Owners' Manual that decrees your inalienable right to get off each time you hump that's been left out of hers? Short answer: Hell no.