This might be long, as it records my learning process for moments such as these.
I will never perform again for people who reach out and grab anything of mine. Even if it is something that I can get away with them grabbing. It's just not polite. Also, to me, they are ruining the magic for themselves. It's like reading a great that you absolutely love and then going back and analyzing each and every sentence. It's ruining the art of the writer, and ruining your enjoyment of such a fine literary experience. It's the same way for magic. Them reaching out for your working material is ruining their experience, and other people near you, and they are pretty much destructing your art.
If you feel strongly about performing to them, which I'm sure you are as it sounds like you all are close, I suggest doing a few self working, doesn't matter if they grab the paste board, card tricks. If they reach out at all, warn them by saying that you will not perform for them again if they reach out.
From now on, when someone I know reaches out I will merely stop performing. Even if others want to see more, I say that I am done. I'll perform again when the person finally leaves. I will never put the blame on the person though. That would be just as rude as what they did. If it's strangers I'll tell them to have a good day and leave. It doesn't matter if I didn't finish the trick, they finished it for them, for me, and whoever else was watching.
Tuesday night a really good friend of mine grabbed my cards after I did a trick. He just couldn't believe it. Instead of enjoying it, he grabbed and grabbed until he got the card. He literally would not give up. He reached out persistantly until he got it. He held the card for not even a second, said, "Oh, it's two cards," and threw it down. He didn't notice that when he threw it down two cards did not get thrown, but only one. And I didn't put up any rebuttal. I didn't let him know that it really was only one card, and that I simply forced it to be picked, and then psychologically made him believe it was free choice by saying over and over, are you sure this one, you sure you don't want to change your mind? If someone wants to destroy what has been set in their mind, let them do it however they want. If they are wrong, let them remain ignorant to what happened. Some people like to be astonished, it's a truely beautiful thing to them, other people take it as some sort of personal insult.
Saturday night there was an absolutely brillant group of people I performed for. I did gimmicked tricks, tricks that required utilities, tricks where you should never have the audience touch the cards. After doing fool proof tricks and not having them ever even move toward the cards, I began doing the other tricks. Eventually I found the one person that was most astonished. I would let her assist in the tricks where you normally don't let the spectators touch the cards. There's one utility trick I do with a two cards as one. I had her pinch the card in the middle and flip it over for the revelation. That whole group genuinely felt that I could do magic by the time I left. If they asked, I would have said it was all tricks, but they never did. They enjoyed what happened, and that's what is important. Those are the perfect spectators to have. If I ever see them again and they want to see a magic trick, I'll do anything I can to show them. I'll go buy what I need if I have to, as they are who deserves to be performed for, and, really, they are the type of people that I want to perform for. They never even freaked out, yelled, or gave some brillant, camera wanted response. They always pretty much just inhaled very deeply, and just stared for a second to take it all in, and then smiled or laughed like they were a child again. It made me feel the same way. I began smiling and laughing at the end of a trick (and not at their reaction, but at the end result of the trick) even though I had performed, rehearsed it, and knew exactly how it worked. Their seeing magic and taking it as magic somehow started to convince me that I was doing magic. That's when I really learned that in some special way I was doing magic. It will be worth it for you, me, and everyone else, if magic is performed exclusively for people will accept the art for the reasons it was created, just like a painting, a book, a poem, and a flower.