Quand on était gosses, on nous taquinait beaucoup à ce sujet.
At first glance, I was under the impression that « on nous taquinait » might denote the reciprocal act of teasing one another, just as « on se taquinait » would do, but then realised that both of them used to be teased by indefinite someone or people — i.e. the second « on » actually referring to "someone/they".
I wonder if this dual use of « on » in a single sentence does not sound ambiguous, especially when the two are placed so close to each other?