When I went to Burger King, got a vanilla shake, and found a strand of electric blue hair in it. Guess who had electric blue hair. The guy behind the counter
Went to IHOP, and ordered chicken salad. When I got it, there was blood on all the chicken bits. I don't know if there was a vein in the chicken that still had blood on it or if somebody cut their hand but

I didn't eat it or pay for it. ********.
Also not gross, but one time my family went to Applebees and waited an hour and a half for our food to come. We finally asked our waitress what was going on and it turned out she had forgotten about us and hadn't even put our order in but continued to serve other people. By that time the place was packed and we had to wait another hour for our food. We legitimately did not go back to Applebees for at least 6 years after that.