Step child's therapy session

We finally got a therapy session with my step child today. They're therapist had to cancel for a hit because if person stuff. If you've seen any of my post you'll recognize the name but my step childs name is Aaron. They were born male but identify as non-binary. They live with us because their mom was abusive towards them for being non-binary. We went to court because my step child was sexually assaulted by 2 boys at their school and to keep them from saying anything they recorded my step child and their boyfriend having sex outside their boyfriend's window and used it as blackmail. My step child is 17 but their boyfriend is 18. Since my step child is legally a minor we tried to tack on child pornagraphy and my they did play the evidence in court and it was shocking because Aaron and there boyfriend were doing some INTENSE BDSM. I mean extremely intense and the most tamed thing in that entire video was their boyfriend calling them a whore and putting them in a cage. We had a talk the next day and you guys have given us good advice on here(except the homophobic/transphobic stuff). They're boyfriend also came by to apologize to us if he did anything that disrespected us and wanted is to know he respects my step child more than anything and my step child could have asked to stop the scene at any moment and he would have. Their therapist spoke to them and then to us and he was honest with us and he said he knows that it's shocking and sort of scary to find out Aaron is partaking in extreme BDSM but that the case was a sexual assault case and in his opinion we were focusing on the wrong thing. Winning a sexual assault case can leave a victim feeling all different types of emotions and he believes we should focus on celebrating that justice was served. He said everything that was going on in that video was consensual and what happened to Aaron that brought us to court wasn't so focusing more on the things that happened that was consensual will be confusing for Aaron. Me and my husband took Aaron out to eat today because we knew they were depressed and just told them we want them to be safe and happy. We even invited the boyfriend along which was awkward. I don't understand BDSM. I still really don't understand how they feel in control letting someone control them but like you guys told me. It's not like I can stop them from doing it. We are just gonna follow the therapist and focus on this victory that those boys are being punished.