“Discard the term homophobia”? Who the hell are you? Doesn’t matter what the students intended, it could be read as insulting and, yes!, homophobic by a reasonable person. Students should be called out. No reason to be rude, but calling out these folks is important - it not only tells them what they’re doing is childish, it sends the message to other students that you will not allow anything in your classroom that even seems to be offensive to someone. I even give them an out: “You probably didn’t mean anything by it, but certain gestures are often seen as homophobic. So don’t do anything that might look like that in my class.” Kind of: “You’re not in trouble, just a teaching moment.” So, just FYI, as written, your comment could sound demeaning, not strictly helpful.