1. Shouldn't his son wash his stepmother's feet? Shouldn't his son wash clothes for his stepmother? 3. It's not for my own son.

Stepmother certainly has no biological mother, and there is basically no problem of washing feet. Nowadays, many people don't help their mothers wash their feet, let alone stepmother. Of course, it depends on the specific situation, so it depends on what situation. When it comes to cooking and washing dishes, if you are busy with work, you can help them do everything you can and live under the same roof, so that you won't be so stressed and you don't have to take it for granted that they support you.