Are you tired of pleading for sex with that lump of blankets lying next to you in bed? We asked sexpert Teesha Morgan to offer some insight into why your partner may have lost his libido, how you can coax it back and when you should call it quits.

Q: What are some of the most common reasons people lose their desire to have sex?

A: There could be lots. Most of them have to do with stress. Let's say your partner has lost his libido. Look at what recently happened - did he lose his job or is a family member sick or are they worried about paying the bills? If it's not stress related, it could be related to diet and exercise. Exercise is humongous when we're talking about low libido and having the energy and drive for sex. If your partner has slipped and instead of going to the gym they're going to McDonald's, chances are that they're not as up for fun in the sack. It could also be medical, and have to do with diabetes, heart disease or some other reason. Seeing a doctor is really important. And then there's a plethora of general, related things, such as that things have fizzled in the relationship and things just aren't that exciting anymore.

Q: Do you find that women tend to internalize their partner's lack of interest in sex?

A: Definitely - it's usually the first reaction: What did I do and why aren't you attracted to me anymore? They relate it to body image issues. Like, I've put on some weight since I had the baby or I'm not as pretty as I used to be. But the vast majority of the time, it doesn't have anything to do with the woman or her looks; it's related to the external factors I mentioned or something internally off with the man.

Q: We've heard that it's normal for the amount of sex a couple has to wane after they've been together for awhile, but are there typical benchmarks?

A: We don't like to use the word "normal," and couples do range from having sex seven times a week to having sex once every two months. It's whatever works for the couple. If one couple is happy having sex once every three weeks, there's another couple for whom that would be cause for a breakup. Each individual is different and each relationship is different.

Q: But would you say that the couples you see who have sex more often are happier with the relationship?

A: Usually, couples that have more sex are happier and healthier in general. Sex is good exercise and it has a bunch of health-related benefits. Couples who engage in sex more often tend to have happier and more exciting sex lives.

Q: So if your partner's interest in sex does dry up, what can you do?

A: First, examine all of the external factors - diet, exercise, stress - and see if you can fix one of those. Try to be your partner's stress reliever instead of their stress inducer. Also, really try not to internalize and blame yourself, and instead focus on communicating your feelings to your partner. Use "I statements" instead of "You statements." So, instead of "You used to want to touch me" or "You used to want to have sex with me," try "I really liked it when we did this..." We call it the sandwich technique, where you start with something positive, slip in something you need to change about the relationship, and then end with something positive.

Q: Bringing this issue can be really difficult. Partners can be very defensive about their lack of a sex drive.

A: That's true. And that's why the sandwich technique is important. Those situations can be really awkward, and people do get defensive - "Oh, it's all my fault the sex has fizzled but what have you done recently?" They go on the attack. If you put the positives forward first, it helps. And if you are having a conversation, one good technique is to avoid sitting eye to eye. Try bringing it up in the car when you're both looking forward and there's music in the background. But trying to not be accusatory is important.

Q: I think people often feel guilty complaining about and confronting their otherwise great partner about their diminished libido - like it shouldn't be such a big deal. But do you think incompatible sex drives is a reasonable deal breaker in a relationship?

A: Absolutely - especially if it's at opposite ends of the spectrum. If your partner wants to have sex three times a week and you're happy with once a week, that's not unusual. Couples are rarely completely in sync when it comes to sex drives. Sometimes one partner prefers sex in the morning, while the other likes sex in the afternoon. Everyone's different. But if there's a huge difference - he wants it five times a week and you want to have sex every three months - then that can definitely be a deal breaker. Sex plays a major role in psychological, emotional and physical intimacy. Without that there, you can just feel like roommates.

Q: There are so many things that are healthy for us that we force ourselves to do - for example, people aren't always dying to get on that treadmill but they do it because they should. Do you think sex is something couples need to do regularly, even if they're not in the mood, just for the health of their relationship?

A: I really do. Sex is really beneficial for your overall health - from diminishing your risk of heart attack and prostate cancer to relieving depression and elevating mood. There's a million positive health benefits, and then on top of that you create that connection and intimacy with your partner that can fizzle and fade over the years. Sex is kind of like going to the gym. If you never go to the gym, you're kind of like, "I guess I should go today." But once you start going to the gym regularly, you start to crave it; you start to appreciate the energy it gives you and how great it makes you feel. Sex is in the same boat - the more you do it, the more you want it.