In this thread some people have mentioned it's ok to do sexual stuff in front of kids. I want to give a real life example that proves how badly it turns out.
The villain of the story is Anthony Weiner. No I'm not making that up, no Weiner is not a nickname, it's his actual name. This is a true story.
Anthony Weiner was a Democrat representing a district in New York from around 200-2010ish. He was married to a lady called Huma Abedin ( Hillary Clinton's most trusted aide ). Both Anthoy and Huma were very much in the public eye as politicians. Anthoy had a problem. He liked to send dick pics to women. One of the women came forwards, then more. There was a huge politcal scandal in the press about it. It hurt his wife Huma terribly. They got through the problem and kept their marriage intact. After Anthoy and Huma got through it all Anthony resumed sending dick pics to women. No I'm not making that up. He was on some hook up websites under the pseudoname "Carlos Danger" sending dick picks. No I'm not making that up. At one point he was taking dick picks on his phone in a room with his and Huma's infant child clearly visible in the background. The dick picks with the child in the background got sent to women just like all the other dick pics. No I'm not making that up.
Any rational person should believe that no one could be that stupid, that the story is made up. It's not. There a documentary called "Weiner" it's an hour and a half long. It is the most incredible thing you will ever watch. I think you can rent it on Amazon Video, but it's been on lots of platforms. You will not believe it.
A man who has no compunction about taking dick pics with his own infant in the background, and sending those dick picks off to women under the psedounym Carlos Danger having already been through a political scandal over sending dick pics is a man who is not capable of seeing let alone respecting boundaries. The boundaries exist to protect children, our partners, and even ourselves. When you abandon or try to undermine those boundaries it only results in harm. Do not involve kids in your sex acts.