Sex at home with young kids...

I saw a post on a facebook wives page and this women asked for help because her 9yr old son would text her during and after sex to "be more quiet" because he could hear his parents having sex. Most commenters said to basically tell the young child to "suck it up" ,"its natural " or a few suggested telling him " well it's how you were made". I was shocked and and said somthing like " you need to be considerate and just keep it down or find a time when hes away or asleep". Wooow,I got a lot of backlash for that comment lol. What do yall think? Should parents be cautious and quiet while having sex or should kids just suck it up because its natural?