The phrase "to constitute a crime" means that something is considered to be against the law and is a punishable offense by the legal system. Full definition
I can promise you that it wouldn't constitute a crime, simply because the section is not designed to stop this sort of transaction. (slaw.ca)
They decide what constitutes a crime and how it should be punished. (reinventalbany.org)
For international family lawyers the judgment is significant in that the court ruled that forced marriage constitutes a crime against humanity. (internationalfamilylawfirm.com)