don't eat them ,,but you could lick them for all to see and then only a real scumbag would eat it
A fly swatter across the back of their hand. If that doesn't work, a cattle prod.
Spit and cough all over em
That would only make them more desirable
step 1. take a very very small ammount of snake poison
step 2. continue doing that, slowly increasing the dosage, to gain tolerance over that particular toxin.
step 3. after you've become completely immune to that toxin, put in in your bagels.
step 4. warn them that, in fact, there is snake poison in your bagels.
step 5. eat one of the bagles
step 6. watch them die (or just throw up, depending on the poison XD)
step 7. nobody will eat your bagles ever again XD
bludgeon them with a mace