[ It takes Yuri a little longer to respond than the first few messages, just because she doesn't really know the situation other than that Bertl's a little awkward for a big guy and that he's probably the one who did something horrible. ]
Be as honest as possible, but show remorse. You obviously have it or you wouldn't be worrying. If you think they might attack you for whatever it is, get a mediator you trust. Don't look for them to accept your apology or be okay with it, just say you wanted to tell them because they deserve to know. Chances are they won't accept or forgive you if it's really horrible, but if you're only telling so they'll forgive you then it's about you, not them.
If you say no, I won't ask again, but if you want to tell me I can probably try to give you better advice that way. That's the best I can do without knowing. I hope it's enough.
text;
Be as honest as possible, but show remorse. You obviously have it or you wouldn't be worrying. If you think they might attack you for whatever it is, get a mediator you trust. Don't look for them to accept your apology or be okay with it, just say you wanted to tell them because they deserve to know. Chances are they won't accept or forgive you if it's really horrible, but if you're only telling so they'll forgive you then it's about you, not them.
If you say no, I won't ask again, but if you want to tell me I can probably try to give you better advice that way. That's the best I can do without knowing. I hope it's enough.