>>Perhaps a more practical approach would be to start with the guys with whom this has been an issue already.<<

This sounds like a solid plan. I also got some tips further down about how to avoid miscommunications of this sort that I will be adding to my rotation of "ways to handle boys*."

*and by boys, I mean cisgendered straight men, because, to my knowledge, that is who I've been dealing with. My approach may be adjusted if I start needing to deal with other gender identities and expressions.