mayo substitute for mustard hater?!

I like the strong tastes like mustard, horseradish, worcestershire, marmite, peri peri, chilli sauce... so the only thing I can suggest is if you can't avoid the mayo, go for low fat mayo.

I also love salad cream which isn't much better calorie/fat wise but they make low fat salad cream too.

Actually 0% fat greek yoghurt is a good substitute for sour cream (or mayo) so it's good for sandwiches and wraps.

Roasted garlic (as a sandwich spread) OR

aioli OR

yogurt (especially in chicken or tuna salads; less rich tasting but lower in calories) OR

mashed avocados (This is a good sandwich spread. Avocados are also high in fat, but it's most monounsaturated fat, which isn't as harmful as other kinds of fat.)

You can try a lentil spread, which you can find the recipe on the internet, also you can try sweet chilli sauce which is a good substitute for other spreads, one other thing I can suggest is avocado which is smooth and doesn't ave an over powering flavor. Hope this helps.

I wish you had told us what you want to use it with.
For a sa;ad try an Herb vinaigrette.
For a sandwich use butter or margarine.
There are many types of mustard from blow your taste buds to hell and back, or a sweet almost sickly taste and numerous in between.

I, also, do the Italian thing and use olive oil with a bit of course salt on bread as a spread.

Good suggestions, people.

Greek yogurt. it is generally used as a mayo substitute.

Use light mayo. It's half the fat and calories of regular mayo. Another option is fat free creamy dressing

lemon juice