The ultimate complement or the ultimate insult?

I was speaking to an attorney last night who works at the law firm where I once worked. He was with two other people (“I came to the reception with my family” he tells me) and I quickly realized that the young man was his son who was currently an undergrad and aspiring to be a lawyer someday. The other, a woman, said “I’m Y and I am the non-lawyer here, I teach dance.” I was about to say “and I assume the two of you aren't the parents here?” [Because there were some little tikes running around, belonging to some young couple, but typically, a college guy was not going to be the dad, even if he did marry early.] My Q was preempted by her next comment. She said “…and my kids, of course keep me busy, though X here (pointing to the college guy) is pretty much on his own by now.”

Whom would I have embarrassed more – the son, in an Oedipal sort of way, for my suggesting that his mother was his wife? The mother, for linking her romantically with her own son? Or myself for being so clueless as to the approximate age of a person?