My girlfriend and I have been doing sexual acts for roughly two months now. And even if she uses her hands, mouth, or we have sex I never seem to be able to get to the finish line unless I do it. we don’t live together so usually I make her finish we spend the rest of our day and then I finish later in the evening. however, i would like to be able to have her finish me especially if we are trying for kids in a few years. Anyone know why this could be? any advice? we are both young adults.