What is Inappropriate?

This has been a week to remember.

The heatwave is still killing us (humidity is something we never think about in Canada until it gets into our sleep), one of my schools asked me to handle two courses at the end of the summer (I need the money, so there goes my summer vacation), and the wall between me and the roommate is still up (thing is to not make eye contact - rather easy to do).  And there was a message from a friend's fiancé that I need to discuss.

I do not know this man.  I barely knew her before she linked up with me on Facebook (from my high school) but I like her.  Then she got engaged and everyone wished her well.  And then he reached me to ask, and I am quoting here:
Kendall,no ill will towards you but i need to ask you a question....Have you slept with xxxx and if so when was the last time?If you did your not the only one

Yep, he asked a stranger if he had done it with his lady-in-waiting.  And he gave me an out by saying that, if I had, I was not the only one.

All the people that I have discussed this with have said that I have done the right thing by telling her about this.  But this is also followed by a discussion about what is now appropriate for discussion.  Mainly, we agreed that technology has changed the game.  But that seems weak to me.  Is it enough to say that web site and email no longer allow us to make mistakes with our thoughts and feelings?  Aren't we still responsible for our own stupidity?

I wonder...