I think the biggest turn on is knowing you turned someone else on.
Harry Potter AU where someone sees Harry in his cousin’s over-sized clothing with his underfed body and hears him casually mention the cupboard in which he sleeps and calls the fucking police
But what if this did actually happen in canon? What if one of Harry’s teachers at primary school noticed him huddled at his desk in clothes that were clearly second-hand and far too big? What if she saw how Dudley would knock him around at lunchtime, and spotted Harry’s baggy socks and sellotaped non-prescription glasses? What if she overheard him talking about his cupboard under the stairs like it was no big deal, and maybe took him aside to quietly ask him about it?
What if she did call child protection service or the police - but when she arranges to meet with someone to discuss Harry’s living conditions, she walks away ten minutes later unable to remember a single thing.