Just the other day I was round a mates (who is a cool guy and loves my magic) and I was doing some tricks when his brother came in (who is not a cool guy and is a bit of a pillock really). Obviously he said he wanted to see some tricks, so warily I did a few for him too. Now he did absolutely everything in his power to mess up my tricks.
First of all in a trick which involves the location of a selected card he lied about what his card was. Thankfully my mate had also seen the card and told me I was right, hence saving the trick. Then in a DL trick, I told him to say stop during an overhand shuffle and thats where he'd put his card. He said stop, grabbed the packet in my right hand and proceeded to thrust his card into the middle of the deck. Luckily a riffle had bent the cards slightly so I could get a break and complete the trick. And finally, when I tried to do another trick he kept saying "I saw that" or "I know how you did that" when I hadn't even done anything apart from put the card back on the top of the deck etc. I completed the trick because he DIDN'T see anything so the trick ran pretty much as normal.
He asked me to do another trick and I said no. He asked why so I said something along the lines of:
"Because you make me sick. This is my hobby and you're going out of your way to make me look and feel like an idiot. It's just as bad as cutting the strngs off someones guitar just before they're about to play you a song or throwing away someones stamp collection. Just because you can't do it and refuse to enjoy does NOT mean I will dignify you by being made a fool of". Suffice to say he turned bright red, mumbled an apology and then avoided for the rest of the duration of my time at my mates house.
If people are insistent on making you feel stupid... turn the tables on them and make them feel stupid. Obviously with only having one example I cant guarantee it will work, but its a pretty safe bet

You wont find much better anywhere and it's nothing - a rigmarole with a few bits of paper and lots of spiel. That is Mentalism
Tony Corinda