Sex life feeling a bit stale? Well, there's one sexual organ most people neglect: the brain. And it's your passport back to Sexual Nirvana. Literally millions of us secretly use fantasies during masturbation, and some of us use them to achieve orgasm during sex. So why not own up to your favourites and act them out with your partner for what could be the lustiest sex you've had in years?

Fantasy 1: He's a virgin - and you're Mrs. Robinson
Why it appeals to you: It's a power game and 'forbidden' sex for both parties, which is always a guaranteed libido-lifter. What you'll need: A 'sexy secretary' outfit works for this one: a long pencil skirt, shirt unbuttoned to show off a push-up bra, stockings and high heels.
The action plan:
The trick to this one is to move very slowly at first. You're seducing him, and he's struggling - torn between ripping off your clothes and worrying about the consequences. (What will his mum say if she finds out? Is she really seducing him or is he reading too much into it?) Say you're going to make a drink for each of you, then lead him into the lounge with your drinks. He sits on the sofa, you sit on a chair opposite, crossing your legs and hitching your skirt up high. He's not sure where to look. Make general chit-chat (the sort of stuff you'd ask your son's friend, if you have/had a teenager), then take the conversation to another - saucier - level. Tell him you don't think your husband finds you attractive anymore. Ask him, Does he think you're attractive? What bits? Why? Let him squirm with embarrassment as he tries to be diplomatic - and tries to hide his erection.

At that point you say, You seem a little uncomfortable and move from the chair to sit beside him on the couch. Loosen the first two buttons of his shirt and rub the back of your hand against his exposed chest saying, Such soft skin. So unlike my husband's. As he squirms, undo the top few buttons of your shirt, take his hand and place it on your breast. Ask him if he likes that.

In between your lurid requests and actions, keep making small talk. Ask him if he's ever made love to a woman before. He'll squeak out a no. Ask him if he'd like to make love to you, and tell him it's okay - you won't tell. Ask him to take off your top and your bra. Tell him to touch your breasts and instruct him on how you like to be touched. Moan and sigh, but remember: You're still the grown-up - so not too out of control. Ask him to stand up in front of you and unzip his trousers. Admire his body, compliment it, say how hard it is, then give him exquisitely tortuous oral sex - stopping just short of orgasm.

Undress yourself theatrically while maintaining eye contact. Let his eyes caress your body, but don't let him touch you. Leave on your high heels and stockings. Pose provocatively and caress your curves. Ask him if he likes what he sees and if he wants to touch you. Then undress him, kissing each bit of his flesh as it becomes exposed. When you're both naked, lead him to the bed, then explain exactly how to make a woman scream in ecstasy. Each touch, kiss, fondle and thrust is his very first, remember. The fantasy ends when he completely loses control - which should happen within about, ohhh, three minutes if you've played your part properly!

Fantasy 2: He's your sex slave
Why it appeals to you: Having someone at your sexual beck and call has obvious benefits. You don't have to worry about the 'no, you first dear' niceties of sex; it's all about your pleasure, and your pleasure alone.
Why he'll love it too: Something happens to women during this scenario; they start suggesting things they wouldn't dare during 'normal' lovemaking. Who wouldn't love a wild woman in his bed?

What you'll need:

• A leather jacket worn over black underwear
• Stockings and a push-up bra
• Knee-high or thigh-high boots
• A blindfold, scarves or old stockings to tie him up
• A wooden spoon or hairbrush

Once you're both in character, order him to sit or lie down, face turned away from you. Blindfold him and tie his hands behind his back, then push him forward into a submissive position. He's now naked, bound and blindfolded - completely at your mercy! Grab your wooden spoon or brush and administer a few short, sharp whacks on his bottom. Start caressing and stroking his bottom, the backs of his thighs, reach between his legs and caress his testicles. Wait until he's moaning for more... then stop.

Tell him it's up to you to decide what he gets and when, and he has to satisfy you first. Turn him around and order him to do whatever you'd like. No matter how pleasurable what he's doing to you might be, push him away when he seems to be enjoying himself the most. Grab his hair, hold it tightly and tell him he's been a bad boy. Administer a few more smacks on his bottom with the spoon. If you're into talking dirty, keep a running commentary of what's happening. If he's blindfolded, paint a picture of what you're seeing: Look at you, you're begging for it. I bet you'd love to be untied. But you're my slave. You have to do every single thing I say. Do you understand me? Are you going to behave? The fantasy ends with you announcing - dramatically - that he's now free... to service you.

Fantasy 3: You're abducted by a stranger
Why it appeals to you: The 'safe rape' is a very common female fantasy - but it's such a far cry from the real thing it seems ridiculous to even call it rape. Passionate and forceful, but never violent or painful, the 'rapes' in our head differ because we're always in control, even though we're being 'forced' to submit.

Why he'll love it too: Being the physical aggressor is taboo for men. Being given a 'harmless' outlet to let loose some deeply primitive urges without being punished is appealing.

He tells you in a low, suggestive voice, that you should draw your curtains before getting undressed at night. He's been watching and fantasising and masturbating while watching you for weeks - and he just had to have you. He knows that your boyfriend isn't due home for hours and that no one else is coming to rescue you either. You remain motionless. You're torn between wanting desperately to be saved and being sexually fascinated by the idea of someone wanting you so badly that they'd risk everything. You don't say a word. Still standing behind you, he keeps one hand over your eyes and uses the other to stroke your breasts, your stomach, your neck and your thighs. You're not sure how to react. You can feel yourself starting to respond physically, even though you know you shouldn't.

As he touches you, he starts telling you exactly what he plans to do to you - in detail. It seems as if he knows exactly what turns you on and talks just the way you want him to, be it seductive and suggestive, or coarse and explicit. When he feels you begin to weaken, he removes his hands from your eyes and you look in the mirror to see him standing behind you, hands on your breasts, his mouth buried in the nape of your neck, kissing you. He's even sexier than you'd dared hope. Your resistance wanes, but you refuse to let him know you're turned on.

Just when you're beginning to relax, he pulls your arms gently behind your back, holding them together at the wrist and using his other hand to continue exploring. He maintains eye contact in the mirror and challenges you to tell him you're not enjoying what he's doing. At first, you shake your head and say you're not. But he tells you that you have no choice; you're in his power.

You resist everything he tries... at first. Then you let him continue. You don't admit that you're erotically charged, but your body is giving you away. You're ready for him. Come on, you want it, he whispers while licking, touching and stimulating you until you can't take it anymore. Finally you let him penetrate. You give in and leave all the initial innocence behind - resulting in a climax so powerful the neighbours bang on the ceiling!

Not sure how to introduce fantasies into your bedroom in the first place? Afraid he'll reject you? Check out my answers to the most frequently asked questions about this sexual adventure.