You don't. There's nothing wrong with a trample fetish, but involving your mother in your sex life will mess up the relationship between you.
The question is why
when you're alone ask her to
You are a sad, strange, little man, and you have my pity.
pay her
Since this is about a fetish it's because it's not normal behavior to involve your parents into your sex life. If not a fetish most would be angry and wonder why she is trampling on them at all.
That's weird
Ask herThat's easy, ask her toask her
ask her to?
you ask her
when they are talking to there friends accidentally walk in front of her
Ask her to
You ask her politely and tell her you have a foot fetish. She has to be able to chose if she wants to be apart of your sex life or not.