How do I tell him?

I don't know how to tell my bf that he's never made me come, to be honest none of the guys I have ever been with have ever made me come and I don't know why. I only come when I masturbate. I feel bad cause he gets me right to the point and then either he comes and is done or he switches positions and I lose it. I feel so stupid cause I should be able to tell him but every time I try I just can't. Anyone have any advice?