Do we have any say over what our kids learn? This past weekend, an incident in a Boston tram forced me to think about whether we need to pay more attention to the people that influence them.

On our way home from a nice dinner in Little Italy, my friends and I boarded a very crowded tram. As the tram emptied itself gradually, we found ourselves sitting across from a middle-aged man with two curly-haired children wearing jerseys. Neither of them could have been more than 10 years old. They could have easily passed for a typical family returning from a ballgame.

The younger child was sipping a super-size plastic cup of cola. The man turned to him and said, "John, I think you're the slowest person I've seen drinking coke." Something in the voice told me that this man wasn't the children's father. A certain distance and a certain mockery that indicated that he was probably their uncle or a close friend of their family at best. There was enough familiarity between the children and him, but there was no sign of a father figure there. This became more obvious as the conversation proceeded.

The three of them were sitting next to a pretty, twenty-something year old girl carrying a large purse. My first impression was that she was also part of the family as the man chatted with her and she responded courteously with an occasional giggle. About two or three stops later, she stood up to leave and he (let's call him Mr. X) remarked, "You better take care of that purse. It's really big and I'm from New York. New Yorkers steal." She smiled and stepped off the tram. Mr. X turned to John's brother (let's call him Sam) and said, "You know, I could have gotten her number if I wanted."

A couple of minutes later, a group of girls boarded the tram and began talking excitedly near the exit. Mr. X looked at them and whispered to Sam, "What do you think? Isn't she cute? You think I can get her number?" Sam laughed awkwardly in awe, not knowing how to respond to this man who seemed to hold the key to an experience beyond his understanding. I wondered what was going through Mr. X's head.

You have to realize that although this man was trying not to be overheard, he spoke certain phrases loud enough for some of us to hear. I stared off into the distance, but had my ear turned in their direction. Evesdropping yes, but in this case, I would rather be discourteous than play willful ignorance.

Mr. X then proceeded to shift his glance across each and every girl in the train with a running commentary to Sam. It seemed that Mr. X had made it his goal in life to get the phone number of every girl he came across. Sam, on the other hand, had no clue what Mr. X was talking about, but he knew this was something new. This was something foreign to his experiences in the school playground. So, as if it weren't enough to demonstrate by example, Mr. X asked Sam, "Hey, what happened to that girl in your class? I thought there was something there. Come on, you can't be shy about these things." Sam grinned and fidgeted around trying to figure out what to say.

Sam's awkwardness revealed itself to everyone sitting around Mr. X and the children. A lady that had taken the vacant seat next to Mr. X and been smiling when he teased Sam initially, grew a frown on her face as she realized that Mr. X was no longer just an over-friendly uncle. This was a man that was straddling that grey area between child abuser and man-child. A lonely middle-aged man taking out his sexual frustrations on a child entrusted to him. A man who would have seemed entirely ordinary talking to friends in his age group had he any, but was entirely corruptive in the vicinity of children. Physical abuser Mr. X was probably not, but abuser nevertheless.

As I pondered these things, I tried to get an identity, a name or an address, something actionable. So my heart skipped a beat as Mr. X pulled out his blackberry when we reached our step. But my excitement was short-lived as he dipped it back into his pocket.

Could Mr. X have been a professional? Very likely. And that’s when it struck me - how completely ordinary looking people belie sick minds. There is a very fine line between a child abuser and a man-child. It's a line that can be crossed easily. So, my two cents to parents everywhere: watch over your children, at least until they're old enough to understand the meaning of platonic relationships. Otherwise, they risk growing into sexually frustrated men like Mr. X.

Disclaimer: The names used in this article are fictional.