Verfolgt, aka Punish Me  

It's about an older German woman who is a probation officer and a teenage boy who is one of her charges. He's obviously a masochist who gets turned on by her strictness and wants her to punish him. She does and thus discovers the dominant side of herself. They have an illicit affair which almost ruins her marriage.  

I could really relate to that boy. Had a few school teachers like that.

Very relevant to TER

Crash (the Cronenberg one) is probably my favorite. The Handmaiden, The Duke of Burgundy, and the Piano Teacher are all also worth checking out if you haven't seen them!

Hands down ATF

BDSM film is Secretary!  

It’s not just the kink (though watching Maggie Gyllenhaal get spanked over a desk definitely didn’t hurt 😏). It’s the emotional build-up, the power exchange, and how their dynamic unfolds in such a tender, erotic, and intimate way.

What I love most is that it shows how BDSM can be soft, sweet, and deeply personal, not just about whips and chains, but about trust, vulnerability, and surrendering in a way that feels safe and electric all at once. That mix of emotional intensity and erotic tension? Pure magic.

THE PIANO TEACHER (2001).

No explicit sex (if I recall correctly). But the twisted power dynamic between teacher and student is so hot.

Brilliant movie made in the 80s. Starring the THEN HANDSOME Mikey Rourke and the stunning blonde Kim Basinger. It's more on the pycho-mental side of BDSM than say 50 Shades. But it's brilliant. The more times you watch, especially as your understanding of SELF and BDSM grows, the more you see in it.  
Rourke went on to make a sequel of sorts, called WILD ORCHID, which was mostly shot in Brazil. It's far sexier but the story is just an excuse to make a soft porn movie. It was co-starring Jacqueline Bisset and I forgot the gorgeous female lead who is the object of Rourke and every other man (and some women) in the movie.  
Definitley worth your time, if you have never seen either one.