All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
We would like to thank you for visiting our website and for your efforts to benefit from it. We ask Allah to grant you that benefit and reward you generously for your concern regarding your dutifulness towards your mother. You should spare no effort in showing kindness and dutifulness towards her. We ask Allah to help us and you to obey Him and to remember, thank, and worship Him as due. Verily, Allah, The Exalted, is All-Generous.
We have previously cited the statements of the scholars on the limits of obedience to parents in fatwas 84942 and 131695. In brief, it is an obligation to obey them in matters that are beneficial for them and which involve no harm to their son.
As for what the son wears, he is not obliged to obey his parents in this regard, as this most likely causes difficulty and inconvenience to the son. In this case, the son should try to convince his parent and seek the help of those to whom the parent may listen. If he wears what he wishes without his parent seeing him, then there is no harm in doing that, and he would be combining the two benefits.
If it is feared that wearing certain clothes, which the parent prevents him from wearing, would result in real harm, then the son is obliged to obey his parent and it is impermissible to go against their command, even without their knowledge, as long as the harm is expected. The criterion in this regard is whether real harm could occur or not.
Allah knows best.