Hi Dawsey,
Well, I bet your not the first man who wants to escape the clutches of the nearest and dearest to go and taste a slice of Thai Pie.
The first idea, is to find out what SHE really wants more than anything. She might always have wanted to go on a cruise, or a ride on the Orient Express.
Find out what it is, then tell her you hate that, but as a xmas present you will pay for her and a friend/mother to accompany her. You tell her you are going on a golf holiday or some shit like that. BUY the ticket for the golf trip, but then get them changed closer to Xmas. Once she sees the proof that you have got tickets for a golf trip, it will ease her mind (unless she really is a viper and she will check at the last minute!). Personally, I dont like this type of lie as you inevitably always get caught out. If you do pull something like this off, then remember to stanley knife the pages of your passport out with the Thai Stamps on.
You wont like this next one, but I reckon you have more chance than any other scheme. Sit her down, tell her you have worked hard all your life and raised a couple of lovely kids, but you feel time is running out and you want some excitement in your life again. Tell her you love her (you have been to thailand, you should be good at lies now
) but you want to go to Thailand at xmas and fulfil some sexual fantasies that you have had for a long time. Tell her she either comes with you and joins in with 3 in a bed, naked massages, ladyboy romps etc or you will go on your own and she will have to just hope Santa brings her a vibrator for Xmas.
Obviously you run the risk of losing everything with this option, but you have now tasted the forbidden fruit. If you never get to go to Thailand again it will eat away at you for the rest of your life. You will begin to despise her and living together will be hell anyway. You may even begin to hatch a plan to hit her over the head with a shovel, then bury her under the patio
Sorry, am I getting a bit carried away here
The only other option I can think of at the moment (dont worry, I WILL think of more!) is over the coming months, just start to look more and more depressed. Start wandering around aimlessly, telling her you arent happy. Go and stay at a friends for a couple of days. Do this on a regular basis, and when you disappear for a couple of weeks over the xmas period, it wont be as much as a shock for her. Obviously you must cover yourself in Sun Block from head to toe, and remember to leave the 'Amazing Thailand' hat at the airport.
Its a tough one. Honesty might be the hardest one, but I would pluck up the courage to tell her you want to blow all your hard earned on prostitutes. She will get over it.