..."Why would you ever ignore a message, which IMO, is far more important than any IT topic ever taught?". That makes sense when hiring for HR, but not for IT, IMHO. As others have said, what is taught in sexual harrassment class should be common courtesy regardless of dept. or people involved. What we found is common courtesy isn't as "common" as it should be, so we have to enforce it for those too self-absorbed to think of others.
You bring up an interesting story. "Consensual" harrassment is its own bad deal for all involved. In your case, I'm guessing those involved were confused that regardless of the target's willingness, it is still illegal. The fact that your co-workers were impeding your work and not helping you should be a "duh!" bottom line issue for a manager, even if (s)he wanted to turn a blind eye to the shenanigans.
Sorry you were being ignored; at least *we're* paying attention to you, (though not in a harrassing kind of way, I hope

).