Definitely. As a teacher, Franco (or anyone) is in a position of trust and authority. They're basically taking advantage of that position, and so abusing that power. It's no different if it's an academic tutor, acting coach, sports coach etc. doing it. And even if it wasn't an abuse of power, it's totally unprofessional.
In discussion of this elsewhere I've seen a lot of 50-something men in academia have been saying there's nothing wrong with shagging a load of 19 and 20 year olds which is entirely what I'd expect them to say.