There are so many reasons to have a child-free wedding. If you're planning on partying all night long with your guests and you want them to feel unencumbered by children, that's a valid reason. If you're having the reception at a more adult venue, I wouldn't begrudge you excluding them. Perhaps if you've got a lot of toddler and baby-age family members, you don't want the stress of a crying baby to ruin the vibe of the ceremony. Even if you don't want any kids at your wedding for no particular reason, I would support you. However, there's a difference between excluding all kids from your wedding and excluding one kid. A father took to Reddit to share the story of his sister excluding his son from her wedding because he has a prosthetic leg. She lied about the wedding being child-free because she didn't want the 12-year-old boy getting more attention than her.