Mayonnaise or mustard? Go!

i don’t like having more than just mayonnaise and mustard, having a third condiment just clouds the issue.
Mustard for the win....always. A thin spread of Hellmans Mayonnaise is nice though. Horseradish sauce is better.....

Ketchup has been something that I haven't placed, or request to be placed, on anything that I eat since the late 80's. I won't even even cook with it. We have a bottle in the fridge, and the wife and kids can have some, but I have to block out the view and sound and sound. It was a traumatic incident. My cousin was there when it happened, and while he will eat ketchup, it will not come from a packet. Bad stuff.....
This is going to sound a little over the top, but I make an aioli with mayo and dijon mustard for the turkey sandwiches I eat for lunch. It’s also great with some herbs with panko chicken cutlets, or grilled salmon, which I don’t make, but do eat.

So I guess the answer is “both.”
If I had to choose between the two, no question It'd be mustard.
WTF is mayo? Some white gooey stuff with no flavor? No, it's gotta have some kick.

.... but there are soooo many more worthy condiments.