Too Close?

Just exactly when is being close to somebody of the opposite sex too close? Was at a friend's wedding dinner today, and sitting next to a friend of the opposite sex. We had our usual friendly banter and heads coming close together occasionally to talk about things we did not want others to hear.

I personally did not have that feeling of increased palpitation or that warm and fuzzy feeling that people get when they are with somebody whom they are having an intimate relationship with. Reason why I am pondering over this matter of over-proximity is due to a comment made by my colleague sometime back. She asked why I did not consider going into a relationship with this friend as, in her opinion, we were quite compatible. At that point of time I did not give it much thought and merely told her my friend's married. As I think back now, I am seriously wondering if the 2 of us are giving others the wrong impression. Maybe we should learn to keep an appropriate distance even though we're both sure we're innocent of any extra-marital affairs...