It sure is a miserable ol' day in Perth today with all the wind and rain but boy our dams sure need that rain (I'll be blowed if the government is gonna make me drink recycled sewerage water)
Unfortunately I can't go to restaurants or cafe's (and most times shopping centres) because people smoke cigarettes outside of these buildings, I have developed a condition called chemical induced pneumonia, which means I cannot go near anyone smoking or having their clothes smell of smoke without getting a bad lung infection or pneumonia. It would be nice to get out of this house and go to a cafe again.
I think you should provide lots of Connors favourite foods for Connor and the guests and set aside 1 plate of salad/fruit/diet jelly food just for yourself.
Life is way to short to miss out on the important occasions in your life.
A Tony Ferguson Shake is worth around 205 calories so if you substitute a sachet and an apple for the cake slice (just for that day) I don't think it will do any damage to your program.
a 100g slice of birthday cake with icing = 250 calories
(so you could omit one sachet and one of your 50 calorie apples to make the calorie intake work out right)
and the cake slice has approximately = 2.5gms of fat
(which is equal to the fat in one TF sachet)
If I were you I'd relax and enjoy your sons birthday, just don't go too overboard with any cake eating
click here for calorie converter