It happens to me a lot.
I work with several young men and they tease me a lot about the way I eat.
I take it all in fun but yes, it is very inconsiderate.
On my birthday the other day, they cut a big square of a brownie and put a big spoon of whipped cream on it and gave it to me, set it down right in front of me and sang happy birthday. I quickly put it in the med room but later, went and had a big bite out of it before I threw it away.
Yesterday, it was a big cup cake. I did just push it aside, never touching it again.
I don't think they realize how hard it is to resist things like that.
At least you did resist. That should make you very proud of yourself.