Me and my husband got called perverts

I have a 14 year old at home. He's not biologically my husband's but my husband has been around since he was 2. His biological father is dead but wasn't a great person to begin with. We have an open door policy with him and he sometimes likes to come in the room and watch TV with us. He came in today and he was wearing a shirt, hoodie and boxers. My son walks around the house in his boxers half the time. Sometimes no shirt and boxers. To me it's no different than him wearing swim shorts. He turned on our TV And we watched movies. It was raining so we all ended up passed out in the bed and it turned into kind of a family cuddle. My sons grandmother, who is his biological dad's mom, came into our house unannounced. She does that a lot. She knows where our spare key is. And came into our bedroom and yelled at my son to get out of the bed and that we are gross. I told her she doesn't run things in my house and she said she will be damned if she has her grandson "laying up" with a man. She then said I'm just as sick and perverted!