London - It is the season to be jolly - as well as pass your flu germs to others at Christmas get-togethers unless you're careful.
That's why etiquette advisers Debrett's have drawn up a list of dos and don'ts when it comes to kissing under the mistletoe alongside customary advice on avoiding a social faux pas this year with the threat of swine flu so prevalent in the headlines.
The first thing Debrett's says is that if you are feeling ill, the sensible thing to do is avoid Christmas parties.
The advice also says a kiss hello is a more hygienic greeting than a handshake. So if you take that approach to greeting or if you just would like to a steal a mistletoe "kiss", the most hygienic way to do so is to briefly touch cheeks with the other person.
"It's medically proven that a peck on the cheek is much more hygienic than a handshake," Debrett's etiquette adviser Jo Bryant said. "People carry billions more germs on their hands so cheek-to-cheek kissing, French-style, is a healthier greeting by far."
Below are Debrett's Nine-step guides for the holiday season.
The 9-Step Guide to Dos
1) BE CONSIDERATE - If you're feeling unwell at the Christmas function, just stand back and observe or, better still, make your apologies and go home rather than risk spreading the lurgy.
2) THE CANDIDATE - Make sure you pick a willing target and that you won't make them feel embarrassed or uncomfortable by asking for a kiss.
3) THE REQUEST - If you want to give someone a Christmas kiss under the mistletoe, it's polite and well-mannered to ask first.
4) THE DECISION - Decide in advance, are you going to proffer one kiss or two? Be cautious with strangers: two kisses may seem over the top, even in a festive environment.
5) KEEP YOUR DISTANCE - Don't get too close before or during the kiss and avoid invading the other person's space.
6) HANDS OFF - It's acceptable to touch the other person's shoulders or upper arms, but don't be a sleaze with wandering hands.
7) RIGHT CHEEK FIRST - It is customary to kiss the other person's right cheek first (that's the one to your left!). Deflect any "meet-in-the-middle" embarrassment with humour or a friendly apology.
8) CHEEK-TO-CHEEK - Unless you know a person intimately, a social "kiss" is actually the briefest touch of your cheek against the other person's. Because there is so little contact, there is a minimal transfer of germs.
9) THANK the other person and wish them a merry Christmas.
The 9-Step Guide to Don'ts
1) Don't go to the Christmas do if you think you have flu.
2) Don't proffer unwanted kisses at the office party, mistletoe or not.
3) Don't reject a kiss under the mistletoe - a festive peck is all part of the Christmas fun.
4) Don't leave a saliva trace - remember it's cheek-to-cheek.
5) Don't kiss on the lips - reserve this for private romantic moments.
6) Don't kiss anyone if you, or they, have a mouthful of food or drink.
7) Don't kiss the air.
8) Don't make sound effects.
9) Keep away from the mistletoe if you've had too much to drink - your social skills will be impaired and you don't want any of those morning-after regrets. - Reuters