The Title IX Final Rule uses the United States Supreme Court Davis definition of sexual harassment, which is conduct that is so severe, pervasive and objectively offensive that it effectively denies a person equal education access. Certain kinds of sexual harassment, such as quid pro quo harassment and offenses covered under the Clery Act or the Violence Against Women Act would be not considered under the Davis definition because those kinds of behaviors and conduct is so sufficiently serious that in and of itself, it effectively denies a person equal education access.
For a speech or expressive conduct that takes place in the educational setting, the Title IX Final Rule will balance that with first amendment protection. Title IX enforcement would ultimately have to be balanced with, say, the rights that would otherwise be afforded to both students and teachers in the educational setting where unwelcome conduct that is just merely offensive would not necessarily be a violation of Title IX. A balancing test ultimately would have to be done. The Title IX Final Rule took this into account because under prior guidance, often cases would arise where cases would be pursued or disciplined for conduct that would otherwise be protected under the first amendment freedom of speech.
If you're dealing with a Title IX case allegation in any capacity, having an experienced attorney advisor will help you navigate the process and will help allow for a fair process and a favorable outcome. They should be involved as early as possible in the process.