Use the old sick trick, worked every time I used it to skip school(long time ago).
In the hours before the meeting make mention from time to time that you don't feel good - add though that you will be fine for the meeting, the ill feeling will pass(makes you look good).
When the time comes, start to get ready for the meeting, get yourself something small to eat(bread or whatever you guys eat as a snack), get into the bathroom, chew it up, make some horrible noise, spit it into the bowel, call for water - wife can see your ill - job done. Wait untill the fam leave and crack open a beer, put the football on TV.