It's difficult to determine the specific reasons behind your mom's behavior without more context. It's possible that she might not have been aware of the discomfort it could cause you or your friends. Some individuals have different cultural norms or comfort levels with privacy, which can influence their behavior.
Here are a few possible reasons, though they may not necessarily apply to your situation:
Cultural norms: In some cultures, changing clothes in front of others may not be considered as taboo or inappropriate as it might be in other cultures.
Comfort at home: Some people feel very comfortable and relaxed in their own homes and may not think twice about changing in front of others, especially if they trust their guests.
Lack of awareness: Your mom may not have realized that this behavior could make you or your friends uncomfortable. Sometimes, people are simply not conscious of how their actions might be perceived by others.
Generational differences: Older generations may have different attitudes towards privacy and modesty compared to younger generations.
If this behavior makes you uncomfortable or if you feel it's inappropriate, consider having a private conversation with your mom about how you feel. It might help to express your feelings calmly and respectfully, explaining why her actions make you uncomfortable or embarrassed in front of your friends. It's possible that she will be understanding and change her behavior once she is aware of your feelings.
Remember that open communication is key in resolving any issue. It allows both parties to share their perspectives and feelings, leading to a better understanding of each other.