Why isn’t my bf coming?

So I have given my bf a blow job and a hand job. He says I am a natural at both but every time I do either one he doesn’t come his dick gets hard and stays hard and doesn’t lose its boner but no come. He has told me that it is hard for him to come to blow jobs and hand jobs. Is this normal? Is there anything I can do to make him come when giving a blow job or a hand job? Any advice at all please!