awkward SO mom story!

So my SO and I recently started having sex after dating about 6 months (yay!!!). Things are going well and we are even talking about a ring! Anyhoo, we spent the weekend at his family's lake house and we took a little time to be by ouselves and "take a nap" as we told his parents. We were actually doing the deed... when along comes his mom who knocks on the door over and over. My man finally has to get up, dress himself and come to the door of his apartment to answer. His mom asked why we never came back, and he is like, "mom we r trying to do a little cardio!"... without hesitation she replies, " ok! Just use protection!"... to the embarrassment of my little ears listening back in our room. He came back and we had a good laugh! I guess she knows now. In case there was any doubt. 🤔😳🤣