I would like to say that I can show discretion and have only one or two bites but sometimes, quite honestly, I can't. I hope that the whole family once-a-year celebration doesn't throw you back to former times.
I have my birthday coming up in the third week of July and I do not want to undo all of the work I have done. I have found that going to a restaurant and ordering one serving is a lot easier than having it around for me to sneak-eat, if no one is looking. In a restaurant you can always pretend you are full ( is anyone ever too full for dessert? Not me!) and then you will have plenty of offers to help you finish your dessert (unless of course, they ordered one too).
My sister always asks for a couple of favorite desserts: chocolate creme pie and banana pudding (Southern style) for her birthday. She told everyone a head of time that these were "hers" and no one was allowed to touch them.
She told me later that to ensure that her teenage (twig) daughters wouldn't have any she put the leftovers in the dishwasher because she knew they never bothered to help load it!
I used to be that way with certain foods too. I admire your courage but it would be hard to have a few bites of something I only have once a year. I am planning on a local Mom n Pop pizza for my birthday. I have had pizza many many places and as far as I am concerned, it is the BEST. Do you think I am going to have one or two bites---no, I plan on a large thin crust Italian sausage, black olives and mushrooms all for myself!! Phase 1 will follow immediately afterwards!
Enjoy your eclair dish on the 4th. Now, how about passing the brats and potato salad??? Hmmmm.....