I find myself quite incapable of demonstrating such tolerances myself (thinking of your post, SpangleChick .My daughter embarked on a horrible relationship, thankfully very short-lived, with a much older man (she was 15, he was 26): I find I am still, over 20 years later, utterly incandescent with rage about this. But worse, I was an out of control teenager myself and far worse things happened to me than a week long 'affair' with an older man. Obviously, I carry coruscating guilt and failure fears. My daughter though, who insists she was 'in control', still considers my rage (and subsequent actions) to have been inappropriate and needless - it almost caused a long painful rift between us...and this disconnect kind of illustrates the complexities since we very much want our children to experience a freedom and open-mindedness to explore their own sexuality, independence and adolescence.
Whilst I came to terms with my own bad decisions, I have been unable (or perhaps unwilling) to move on from my failings as a parent, including double standards and hypocrisies aplenty.