I've done this once and I got caught! I'm a bad liar, which is why I almost never lie. I bought a really nice appetizer from a gourmet food shop and took it to a party. I unwrapped it and put it on my own serving plate but I forgot to take the bottom lining off, which had the shop's name on it.
So when my friend asked how I made the cheese ball, I kind of hemmed and hawed. By the end of the night, the label on the lining was visible and she came up to me and laughed about my "cheese ball" abilities.
I was embarrassed, even though she didn't really care, but I'm known for bringing my own concoctions.