I don't think we know yet what anybody may have ever seen or heard. I suppose he must have been good at covering his tracks and not raising suspicion, since it went on for such a long time. But it seems odd that anyone could be so good as to get away with it for so long either. And then... what is there to see? A few spoons in trash can? I certainly wouldn't have guessed that something so... diseased... was going on. And then I think too that nobody wants to let themself believe anything so heinous about someone they know well, and it's tough to be he first one to make an allegation like that, especially if it's just based on hard-to-describe little suspicions without direct evidence.
Unless it’s just a peculiarity of my twisted DNA, while I have absolutely NO idea what semen would taste like (and never had any plans to test that and don’t now) I can very much attest that it smells locker room raunchy. (I live far more virtuously today than at the time I found this out, and no a close nose was not needed to notice it.) It would have been an automatic gross out experience for these kids. If my post gets zotted I understand... please don’t zot ME... but really. The complaints must have been intense.
The spoon and cup that they found in his trash can had tested pos. for his DNA.