It's a tough situation when one lives in a parent's home. Does your boyfriend work? Could he perhaps find you two a place to live while you wait for section 8 housing? If he does not work or contribute at all financially, then you two will have to live by your mother's rules while you are in her home.

I totally get where he is coming from, it must be frustrating to not have that privacy. But at least you two have a roof over your head, and food to eat. Perhaps in the future you two can make sure you're not naked while hanging out in the room, in case she comes in unannounced in the future. Frankly, while in her house, it is her rules that you must obey.