I was in the bathroom, cousin in law suddenly

This is quite normal.

You and your mother-in-law are both women, and it's nothing to see, your husband is her son, and the mother and son are nothing, but your father-in-law comes out in briefs, which is really indecent, you just let your husband talk to his father and let him pay attention.

It's been a few minutes now, get out of here, wait until your brother is suffocated, and you still have time to ask.

Poor ventilation, lack of oxygen, anemia can all contribute to the situation you are talking about.

The bathroom is damp, and flying insects like to stay in dark and damp places.