Is it normal for mother-in-law to wash her husband's feet and wipe them?

Actually, the world is not normal. Your husband is an adult. You should wash your clothes and wipe your feet yourself. Drowning is like killing a child!

However, this is a matter between mother and son after all. If two people agree with this mode of getting along, if you jump out and object, it will only destroy the feelings between you and your husband. My mother-in-law might do this for you. I hope you can serve her son in the same way.

You just won't wash him anyway. When it's just you two, let him do it himself.