My boyfriend cannot reach a climax during sex. We are in our mid-30s, and are both physically fit. Although he does not have a powerful sex drive, he can achieve an erection and maintain one, but he never ejaculates during sex. This problem is starting to affect our relationship as well as our sex life. Is this impotence? Can this be treated? Please give me any advice.

To answer your question I would need to know more. First of all, can he masturbate to orgasm? If he can't, then he has a problem that needs to be addressed first of all by a urologist.

If he can, then he's suffering from what is called retarded ejaculation. One simple cause of this can be that he is afraid, at least subconsciously, of impregnating you. Even if you are using a birth-control device, he might not have enough confidence in it. You could try using something else, like a condom that he can see and feel, and perhaps that will help him. If that's not it, then the underlying cause is more deeply seated and he should consult with a sex therapist.