For someone who carries their beliefs to the extremes that you do, oral sex would contravene what you term your “moral standards”. Perhaps beliefs is a better word for your approach to life than moral standards, as I refuse to believe that your interpretation of the rules of being a vegan are widely accepted. Certainly I have never come across it among the many vegans I have treated. If you adopt a strict interpretation of vegan rules by adhering to the dictionary definition of veganism your conclusions are (just) understandable. In my opinion, obedience to all laws, rules and customs should have the aim of honouring the intention of the law and not its letter. If you could do this, your problem would be solved.

In defence of your opinion the Oxford Dictionary defines a vegan, as opposed to a vegetarian, as “a person who does not eat or use animal products”.

There could be hardly any substance that is more essentially animalian than semen, or one that has such an animal origin, even if the animal is your boyfriend. Not only does semen contain fructose, (a sugar, hence the reason why semen is so calorific), but also proteins and other chemicals including trace elements. It is also the habitat for the sperm, which are alive and swimming in the semen that happens to be the nutritious pond in which they survive.

Even if you didn’t swallow, you would still be using — by your standards — an animal product although you were not consuming it. When I met vegans in the surgery or clinic, I usually judged the strictness of their commitment to their principles by whether they were wearing leather shoes and belts or plastic ones. I have never asked them about oral sex or other sexual practices, but presumably all women who wish to become pregnant use their partner’s animal products in order to achieve this.

To follow your beliefs as determinedly as you want to would ensure that vegan beliefs didn’t exist in a family beyond a single generation. From talking to vegans it seems that the essential feature of their belief is to show respect to animals and to regard them as equally important as human beings. This hasn’t much to do with someone’s sex life with their boyfriend.

You don’t tell us whether your boyfriend is also a vegan. If he is not, it would be difficult to know whether any problem he has with you over your anxieties about oral sex is because he is objecting to the nuisance and irritation that this is causing him, especially if he doesn’t share your opinions. A more likely explanation is that he has an objection to using condoms.

Most men, perhaps sometimes unwisely, when in a long-term relationship are averse to using condoms. There are many suggestions in books on sex and in pamphlets designed to encourage safer sex of methods of fitting these that can be included in foreplay. None of these seemed to meet with the approval of the patients I looked after. The same books include hints about choosing flavoured condoms but the flavours have a synthetic taste, unlikely to appeal to a gourmet.

Remember that for anyone who interprets being a vegan in the way that you do, all sex — whether oral, mutual masturbation or penetrative — that resulted in ejaculation would contravene your rules. This must be nonsense.

SUZI GODSON

I wasn’t sure whether this was a meat or gravy issue so I called the Vegan Society (www.vegansociety.com) for moral guidance. When I read out your question over the phone to the public relations woman, her rather flustered response was: “Oh goodness, maybe I should get back to you on this one.” Which she did. And here, straight from the horse’s mouth, if that would be appropriate, is the official party line from the Vegan Society: “We work to promote lifestyles based on the non-consumption of animal products and don’t really deal with the consumption of human animal products.” In other words, it wasn’t sure either.

It did, however, recommend the lubricated Condomi condoms sold at its online shop, £1.75 for a pack of three in slightly puzzling sizes: regular, extra large and studded. Fortunately, brushing up on veggie sex was easier elsewhere.

At Nerve, America’s coolest, smartest, most honest sex magazine (www.nerve.com), Tana, 29, a vegan for four years, navigates herself and her principles around this thorny issue by refusing to swallow “if the semen belongs to a guy who is not a vegan”. She has no problem with vegan semen and says that, as an aide to fellatio, a cream made from tofu is good.

At www.veganporn.com, a site that you really ought to visit, Incredible Weirdo defends a vegan’s right to swallow by asking: “How much of your own spit do you swallow everyday?” And ZoeB makes a fair point when she says that oral sex can be justified for vegans because “animals don’t consent to being eaten”.

Though you wouldn’t think that taste could possibly matter to people who choose to eliminate two out of the five food groups, it does. Particularly when it comes to oral sex. Everyone at Veganporn says that vegan partners taste better (well, they would, wouldn’t they?). Ryan admits that: “I have gone down on only one vegan but I must say that her taste was far better than any carnivore. I date only vegans now.” Marie agrees: “Honestly, my ex-boyfriend was a vegan and his semen was much sweeter than the carnivore I’m dating now. It’s a completely different taste. As unbiased as I can be, just purely talking about sex the vegan boy tastes better.”

I’m not sure whether your boyfriend is vegan too but, if he is not, you might want to consider putting him on a veggie detox before you go anywhere near his penis. The digestion of dairy products and animal flesh has deleterious effects on the taste of sperm. Mind you, so do garlic, onions, Brussels sprouts and veggie curry. Fortunately, there are ways to sweeten bodily fluids; pineapple juice, bananas and papaya are good, as is parsley because it eliminates body odour and freshens breath, too.

Beer also sweetens the taste of semen and, fortunately, the big brands can be classified as vegan. Budweiser, Red Stripe Lager, Kirin, Cobra, Heineken Export, Hoegaarden, Rolling Rock, Beck’s and Kingfisher. Though beer isn’t the place you’d expect to find animal products, many are filtered with animal ingredients such as “isinglass” (derived from fish) or “bone char ” (charcoal derived from animal bones).

The filtering process leaves only trace animal residues in the final product, but if you are experiencing a moral dilemna about whether or not to swallow your boyfriend’s semen, then you sound like the kind of girl that this would matter to as well.