http://anarcho-capitalist.org/wp-content/pdfs/Rothbard%20(Murray)%20-%20The%20Ethics%20of%20Liberty.pdf
Chapter 14 is on
Children and Rights (p. 136 in the pdf document).
p. 139:
"In short, every baby as soon as it is born and is therefore no longer contained within his mother's body possesses the right of self-ownership by virtue of being a separate entity and a potential adult." ... "Applying our theory to parents and children, this means that a parent does not have the right to aggress against his children..."
Are you asserting that under anarcho-capitalist theory a society at large has a right to intervene by trespassing upon a sovereign individual's property and to use force to prevent two sovereign individuals from engaging in sexual acts that they both want to engage in?
If so, please present your evidence for such an assertion.