Q: I'm a 25-year-old heterosexual woman with absolutely zero libido. I have never cared about sex, and it is beginning to be a serious problem with my boyfriend. I'm not on any medications, I'm in great health and I don't have any sexual trauma in my past ... I just think sex is kind of pointless.

Orgasms seem like a lot of work for very little reward. I'd rather read a book! This is my first serious relationship, so I'm just now realizing how little I care about sex. (I only had one-night stands before.) I don't know what to do to make myself like it. We've tried everything — books, positions, toys (we can't afford counseling). Am I one of those asexual people?

A: Since it seems you do have orgasms, you're not asexual. But perhaps you aren't fully sensing the entire orgasm, and are experiencing more what is called missed orgasms. Or, it may be that this relationship isn't the right one for you.

If you're feeling very little passion for him, then that's not going to make you very aroused. But before you do anything drastic, I want you to spend some time every day thinking about sex. You may require a long time to become aroused, and if you're thinking too much about it when you are in bed with your boyfriend, that also could be preventing arousal. But if you think about sexual situations during the day, for a couple of minutes maybe three to five times a day, that might permit you to become more easily aroused when you're with him at night.

Also, if he's not being very romantic, he needs to do a better job of that. Try that for a while and see if it helps, even a little.

Q: I'm a 17-year-old straight female, and for the first time in my life I've started feeling sexually aroused by body parts on a male, specifically abdomens that are a little paunchy. The problem is that I can never stop thinking about what I'm aroused by during the school day, since I see guys like that everywhere. I'm afraid all these hormones will get in the way of my grades.

Is there a way that I can control this? I'm confused by all these feelings, since I never cared for relationships or guys before, and then all of a sudden I'm getting turned on by them in ways I've never experienced before.

A: While society seems to expect that you're supposed to feel sexual as soon as your body changes, that's not always the case. People develop differently, and so the fact that you've only now begun to develop sexual feelings is fine and is nothing to worry about.

Figuring out how to push those feelings aside is something that teens have been trying to do since time immemorial, and it's not easy. But developing the ability to concentrate, to push aside distractions, is something that will serve you well throughout your life, so rather than look at this in a negative way, accept the challenge and really work at being able to concentrate on your studies. Reading what you wrote, which shows that you are a young lady with a good head on her shoulders, I have no doubt that you will succeed.

Q: I read that any vagina can adjust to the size of a man's penis. I disagree. I am a small female. What kinds of tests could I ask my doctor for? I know sex is important to a relationship, but I know I am not developed. It has been hard to explain the issues to doctors. I am frightened to get into a relationship with a man because of sex. Are some vaginas smaller, or do I have a disorder? If you can have sex only in certain positions, what is wrong? Basically, I got divorced over this.

A: Your gynecologist has seen thousands of vaginas, so just ask your doctor what he or she thinks. Be very open about it, and if you don't think your doctor is giving this question the attention it deserves, then find another doctor. Assuming that he or she says your vagina should be able to handle any size penis, then there's a good chance that your problem is psychological.

If you are very nervous and subconsciously are tightening your vaginal muscles because of it, then that could be the root of your problem. A sex therapist could help you with that problem. So, first get a checkup — more than one if needed — and take it from there.

Finally, if a man really loves you, the fact that you are limited to only some positions is not the worst thing in the world. As long as you and a partner could have sex and both find sexual satisfaction, that is what really matters, not how you arrive at a satisfying conclusion.

"Dr. Ruth's Sex After 50" (Quill Driver Books) is Dr. Ruth Westheimer's latest book. Have a question for Dr. Ruth? Write to her at drruth.com.

Distributed by King Features Syndicate