Sex and noise tmi

Ok well a bit tmi but me and my husband were up till 3 last night and were having sex we live in a town home with neighbours right next to us on the other side of the wall in our bedroom and my neighbors happen to be my mom and stepdad that recently moved in a few days ago, they just called me up asking what all the noise was about at 3 in the morning they said they heard banging I told them it was my daughter banging on the door I am npt really sure if it might have been her or us how would I prevent thwm from hearing us have sex. I really don't want them to hear us have sex we weren't even that loud with moaning and im not sure why they heard banging im a bit embarrassed it might have been us they heard.