This comes from an actual experience,
embellished true but based on fact.

Faux-pas

One should be careful, I found,
much to my horror,
when making a conversational intrusion.
Else you could make
a social faux-pas,
by jumping to the wrong conclusion.
As I walked up the lady said
"but they don't look
at all like brothers".
To which another replied,
"Well same father
but two different mothers."
Now good chance would have it
I kept my mouth shut
no ifs, ands or buts.
For as it turns out
they were actually talking
not about grandchildren but their mutts.