I put Italian dressing on grilled chicken (not as a marinade, but after).
I also put parmesan on pizza. I'm surprised your mom thinks this is bizarre; heck, Pizza Hut puts containers of parmesan on the tables here just for that purpose!
A1 steak sauce on top of chicken fried stead with white gravy.
I think it's delicious, and wouldn't eat a chicken fried steak any other way, but I get the weirdest looks from waiters whenever I ask for the bottle of A1.